My bump steer test data is here: PROFORGED .5 TALLER BALL JOINTS
Stock bump steer isn't great but you probably won't notice it on the street. But any chassis mods you do likely make bump steer worse. Tall ball joints increase it due to geometry changes pulling the top of the spindle inward more in bump. Wheel center contact point to suspension geometry "Instant Center" length is what changes from stock and changes the arc the Steering Knuckle travels. Stiffer A arm bushings reduce deflection, but the factory bump steer was designed-in to compensate for this deflection. In a hard corner, the lower A arm moves inward and the steering linkage was set up for toe out gain in bump to compensate for it. So once you reduce deflection in the bushings, you don't need built in bump steer to compensate.
I usually recommend a .5" tall upper ball joint only and .5" taller outer tie rod end to keep bump steer as low as possible. If you add more than the 3.5 deg positive caster in my test, it rocks the spindle rearward, lowering the outer tie rod end more and this will further reduce bump steer by a small amount. I wish I'd measured it at higher caster but ran out of time.
The Hotchkis TVS is a great system, we ran it on my wifes second gen and it's a great foundation for mild to wild builds with some tweaking. We found the Bilstein shocks to be a bit soft for hardcore autocrossing and upgraded those. The spring rates are stiff, 600 front, 175 rear, and you feel bumps more on rougher roads which is the main downside to that system. The shocks you use need to be tuned to the stiffer springs with more rebound, or use rebound adjustable shocks. The Hotchkis multi leaf springs have a thicker lower leaf that acts like a built in traction bar and resists wheel hop very well. They put a lot of work into that system and it performs well with a cost in ride if roads are at all rough. Leaf springs are heavy and the high unsprung weight hurts ride quality. My wife didn't mind the stiffer ride as much as I did so every person has a different goal for ride quality.
We tried a Prototype Hotchkis 3 link that rode much better. I could tell the improvement riding as passenger before we even got out of the parking lot. It had good traction on acceleration with adjustable anti-squat & adjustable panhard bar for handling balance adjustments.
The Ride Tech Street Grip is all about reducing friction in the pivots by using Delrin bushings, letting the suspension do the work of absorbing bumps. It's tuned for the street and a great option for most guys. Tuned more like a performance street car and less race car, it can still handle very well. I would give this system a try. You can always add more parts, like tubular upper A arms later for more caster but this system works very well as is. I'd add .5" taller outer tie rods to reduce bump steer. The only way to really nail down bump steer is to actually measure it on the car and modify the linkage to fix it. Baer sells the Baer Tracker adjustable outer link, but it probably won't do more than the Proforged .5" tall outer tie rod end and the Proforged end is longer lasting sealed & greaseable. A bump steer fixed car is a thing of joy... The composite monoleaf springs have very low unsprung weight and dampen road shocks for probably the best rear ride quality you can get short of a link suspension system. Street Grip lacks a rear sway bar but if your front and rear tires are the same size, it should handle ok. If rears are much bigger, a rear bar may be needed depending on how hard you want to push the car and what you are doing with it.
The regular Ride Tech system with tubular arms, Coil overs, tall spindle and tru-turn steering linkage fixes bump steer pretty well, not perfect but close. The tall spindle fixes the camber curve, the A Arms allow you to set high amounts of caster, 5 to 7 degrees. Their rear 4 link has a smoother ride than any leaf spring system. The spring rates can be changed more easily with coil overs for tuning and setting ride height. and softer coils can be used to tune it for street use. The Tru-Turn system moves the outer steering arms out of the way, so you can fit wider front tires. I think a 9" rim is max for stock steering arms, depending on your wheel offset. 8.5" to be safe.
I'm going a bit beyond this threads question here to show what the next level is:
When you want more front traction for even better cornering, fitting a 275 X 18 tire is tough to do. It's easier on a 69 Camaro because they have around 3/4" more room. Not saying you can't do it, but things have to be perfect and still may require some sheet metal bumping. A higher ride height helps with room too, so you might build a street driver at a not super low ride height and a 275 works with exactly the right backspace, where a low riding corner carver car won't. An aftermarket front sub gains you 2.5" more room per side due to narrower frame rails. This is why we run Art Morrison front subs on our cars. We also gained 3 hole adjustable sway bars and easy access to the shocks for tuning and spring swaps. We also gained more frame torsional stiffness which is very much lacking in a first or second gen Camaro.
When we added the AME IRS system the ride was like a late model Corvette.
When the rear is minitubbed and you start running 315 or 335 rear tires, then you can't get by with 255 or 275 front tires. I wouldn't run less than one size smaller front tire compared to rear. A 275 rear with 255 front is doable in theory but a non minitubbed rear is going to be very tight at a low ride height & you hit bumps. If you are looking at the left rear wheel, the 2 oclock position is where the tire will hit the fender lip, even when pushed inwards to where the tire hits when cornering hard. The fender sweeps inward behind the tire centerline and creates tight clearance.
To kinda start over, we are looking to improve the following:
Wider than stock tires for more traction. Lower profile to get faster steering response. (don't go crazy here)
Better feeling steering box, 12:1 firm feel- 12:1 firm feel AGR retrofit box or similar
Solid subframe to unibody mounts. You don't want sub movement relative to the unibody.
I don't think subframe connectiors are needed on a street driver. If you have a lot of horsepower and big tires, then it's a good idea.
Fix/Improve Camber curve - tall ball joints or spindle
Increase static Caster from stock 1/2 deg positive to 5 to 7 deg positive. Lowers steering arm for better bump steer, Tubular upper A arms
Improve or at least don't make bumpsteer worse. - .5" taller outer tie rod ends (Proforged)
Firm suspension bushings, Delrin is the only good choice, Rubber second, Polyurethane third. Polyurethane has stiction and hurts ride quality and handling. Delrin has way less friction.
Control wheel movement with better shocks. Increased spring rates require more rebound stiffness in the shocks. Single adjust shocks allow you to tune ride to your preference.
Stiffer sway bars to control chassis roll. Keeping the chassis more level, allows the tires to stay in better contact with the pavement.
Ideal rear leaf springs will isolate or dampen vibration, weigh less and not allow wheel hop. The Ride Tech Street Grip leaf springs are supposed to work well. When you go to a multileaf spring, control is good but unsprung weight goes up and isolation goes down, - hurting ride, keep rubber front eye mounts to help.
For street use, I'd like to see a front spring rate around 380 (Z/28 rate) to 450, rear rate of 175 with rebound adjustable shocks. I'm assuming around a 255x18 tire to 275x18 for example or smaller. If you have larger or stickier tires than this, then higher rate coils will be needed if you intend to drive it really hard. If street use, these rates are OK if you are not super low ride height.
I did't mention seats, I think stock seats suck for ride quality. The springs in the stock seat bottom make the driver bounce much more than they should. The seat spring rate is exactly wrong in my opinion. Aftermarket seats are better.