why not do a carb'd LS1? like this one....
http://www.camaro5.com/forums/showthread.php?t=21225
Efi can be cheap as long as its tuned properly.
ls series motors are becoming cheaper to build and mod than in previous years. you can get a running ls1 for less than $1000.00
hell, even a 5.3L can be made to put out some serious power. a 6 speed is nice, the trans will depend on your wants and needs for the car. tho my A4 in my 94Z would let me cruise @ 80 around 2100rpms (till I put the stall and the gears in it)