[93GTDIN]

You're not going to be feeding anything to any car with an LT1 with an automaic convertible. You either need a new drivetrain or a big power adder.

Now to answer your question....

Crank and rods: Use what you've got, get them machined.
Pistons: get forged aluminum pistons (Arias, TRW, SRP, all are good)
Heads: AFR 165 or Trick Flow TW's both good heads
Exhaust: Makes little to no difference. Longtubes sound good.
Bearings: Clevite
Rings: Federal Mogul
Gaskets: Mr. gasket or Felpro (90 dollars or so for a kit)
A one piece rear main seal is a MUST
lets see, what else...
go ahead and spend 100 on a new set of lifters, and you will definitely want 1.6 or 1.7 roller rockers, depending on if you stay with the automatic, what you want from the car overall, etc.

All other stuff is reusable, have fun.