Hello guys,
Thinking about changing my original std seats for something a little more comfy. What are the best donor seats to look for comfort and fit wise?
I will be adding a track extention to slide it back about 2" more to fit my 6'1" frame.

Do a search for late model Firebird and Camaro seats and you'll find plenty of info. I have a pair of '97 Firebird seats that one day I'll recover and install. Bear in mind that the Firebird seats have removeable headrests, while the Camaro headrests are integrated into the seat.

From what I've been reading alot of guys are using Fiero seats as well. I'm in the same boat as you at the moment trying to decide what to use. I have 5 used original seats for my 67 to choose from (all need recovering) but may go with something a bit more comfortable. Stock 1st gen. seats never were very comfy. I used to manage a salvage yard and I'm sure they'll let me take a set of Fiero seats to try and see how they look and fit.

Any one ever use Gen 3 seats? I saw them in a 68 but they looked to sit very tall. Any thoughts?

I used 98 Grand Am seats in my 68. Had them recovered to match the rear seat.

Having owned a 1st, 2nd, 3rd, and 4th gen Camaro, I think the 4th gen seats are by far the most comfortable of the group. They can easily be made to fit in the 1st gen chassis. (I bought a pair of 97 buckets and they measure out fine.) The only problem is they 'look' wrong. But to me, that's mostly because the upholstery pattern is wrong. Someone currently makes 1st gen style houndstooth seat covers for 4th gen seats. I saw them on site that concentrates on those who want to turn their 1st gens into protouring rides. I think they were around $400 for the front seat upholstery alone. I like the idea, but would prefer a standard vinyl interior style. That they dont make. No offense to those that get aftermarket seats (scat, etc), but the big side bolsters just dont look right.