You will find more selections in aluminum with a 17" wheel....Some guys are able to run P245/45/R17 all the way around....Others will run P275/40/R17 on the rear and P245/45/R17 on the front. The P275/40R17 was used on the back of Corvette's beginning in 1988 or 1989 if I recall...It was first used on 3rd gen Firebirds with the introduction of the 1991 Pontiac 350 SLP Firehawk...Some 4th gen 'Maros & 'Birds can be found with that size as well.
The P225/70R14 has a larger overall diameter than your typical Camaro size. If your speedometer gear has been configured with that size you may see a noticeable difference going with a size which is smaller in overall diameter....
On first gen's the radial equivalent to bias ply tires was P195/75R14 which was OEM by the very late 1970's on Regals, Ventura's, Cutlass', Nova's and even 2nd gen's......
The early 3rd gen 1982 - 1987 Z28's came with P215/65/R15 which was used on FWD Cutlass & Regals as well even in 1989...IROC-Z's were available with P245/50R16 from 1985-1990 and all 5.7L IROC's had 16" tires & wheels.
What I am getting at is this: The tire sizes on all Camaro's were generally between 25.5" at their smallest and around 26" at their largest. Keeping within that size will reduced your load on the suspension and help prevent pre-mature wear on ball joints and other items. This is based on my experience in the auto industry from 1989 - 1998...
Here's a helpful chart http://www.1010tires.com/TireSizeCal...?action=submit
As far as Billet, the name is Waaay over-rated! I have a billet MSD distributor in my car and that was corroded as all hell with very few miles on it.
Steel wheels can take potholes better if you drive in winter in Chicagoland, but the manufacturing quality has improved alot over the years on both tires & wheels and they hold up better today. You can also get P245/50R16 tires MUCH cheaper than 17"....I've seen excellent condition P245/50/R16 sets of tires for as low as $150 locally on craigs list with maybe 5k miles on the tires, good shape, 3 years old all because some 19 year old kid wrapped his Firebird or his IROC-Z around a tree and parted out the car.
17" will handle better, but expect to pay more $$$.....I hope this info helps you out!!