Well do you want an LS1 with a 6 speed manual tranny or the 4 speed auto?
LS1 + T56(6 speed manual) are usually in the ballpark of $3000-$4000 for the engine all accesories, harness, and pcm. Im not sure what years are the best. They upgraded the intake and heads I think in 2001, but Im not 100% sure on that either.
LS1 + 4L60e is usually about $500-$700 less than the T56 combo.
The LS1 is a 350cid(well its a little under 350, something like 346") Multiport EFI engine out of a 98-002 Camaro, TA, Firbirds and Corvettes(they also came in the 97 Vettes). Stock they are rated from 305-320HP depending on year and what it came out of.
Then there is the Z06 engine LS6 which is rated at 405HP.
Look at some of "mas280" posts. He is running an LS1 in his car and his putting down 398RWHP with just a cam, good intake, and good headers. And he runs a 11.2 in is car!
The LS1 is the latest and greatest on here and now everyone wants one after seeing just what they can do with very minimal mods to the engine. If you supercharged one you would be just about unstoppable on the street.
Now does your car already have the big brakes and good suspension? If so you got that covered so no money needs to be spent there. Since your car is new you wont need to do body work or interior.
The only thing that concerns me is trying to make your gauges work. Im sure theres a way though. There always is!
Guy