Which camera/lens for macro indoor snall object remote/w/tripod

I need to shoot marbles (little round glass objects) and pocket knives and small stuff but with amazing detail in a totally controlled studio environment (remote, tripod, lights, etc) and occasionally manual focus for transparent marble interiors and I hate my SX30is (cept for snaps and pet movies)!

I don't care about outdoors or video or IS so what will a T4i/EF 100mm f/2.8L Macro IS USM do for me that a T1i/EF 100mm f/2.8 Macro USM wont at 1/2 the price?

Any recommendations for none of the above (w/alternatives?)

Thanks!