Classic Industry has a great catalog! It has pictures of everything! BUT, not all of their parts are good quality.
I usually try to by stuff made in the US. Sometimes that isn't an option. I have about 12 places I buy parts from. I research what others have bought and what is offered from each vendor.
You may want to go to Team Camaro, camaros.net, and search around to see what people are using. You will also get a ton of help from the people there since they have done it all before.
1968 SS w/ 1966 427/425 Sequoia Green w/ Bumble Bee stripe. Always working on it...
Drooling over the ZL1s. It will be my next car if I can manage to pull it off...