I think it really depends on what you are trying to accomplish with the suspension and how much you're looking to spend. If you're a great fabricator, you can drop in a whole new chassis with the suspension done from Art Morrison. However, I'd say the most popular suspension products among the Street Rodding world would probably be from Detroit Speed and Engineering. In fact, they were chosen by 4 of the top 5 2008 Street Machine of the Year finalists.

Global West has some nice bolt-in stock replacement parts for the Camaro. A friend of mine really likes the Global West stuff he has on his 1965 Mustang.

Also, Hotchkis makes some nice stuff. You can get individual pieces and build as you go, or buy a complete kit they call TVS (Total Vehicles System). The TVS kit looks nice since it takes some of the guesswork out of selecting suspension parts.

Highland Daytona Racing also makes a very trick suspension kit for the early model Camaros, also called the Max-G. Its not cheap, but looks sweet.

There are a number of excellent choices available for the first gen Camaro. You can research options at two excellent virtual communities: Pro-Touring.com and Lateral-g.net. My 1968 Camaro uses an aftermarket tubular front clip that accepts late model Corvette suspension. Rear suspension consists of a Jake's Rod Shop torque arm kit.
Regardless of budget, you can achieve excellent results with bolt on parts or really step things up an aftermarket clip up front as well as rear suspension that replaces leaf springs with links. Almost all of the choices provide improvements, so there's no need to go all out unless you want to.
...And don't forget about tires and driving skills. Those are the two most important resources. If road course track time is not practical, find a local autocross club and get hooked up!