hrmm, you don't need the tb really, only reason i threw mine on was because i got it for $55 shipped. About the cam, you mentioned speed density it might be best to switch from speed density to MAF. I'd go with H/C/I & Gears, i put 3.73 on my 95 gt 5 spd and i love them. One thing concerns me, since your taking out a loan for performance parts what happens if the engine goes? If you get something like a blower, make sure you get it tuned properly, because if your burrowing money for performance upgraded and something goes wrong
Did you do a 4 cyl. to V8 swap in your car? Just curious cause it says it is an 89 LX in your sig and if it came factory with the V8 it should have mass air. Is it an older (87-88) engine. Anyways, if I were you I would do a maf conversion if so and a h/c/i. That should keep you well within your $2500. If your dad is paying everything over $500 on your paint job I would definately take advantage of that and have that done also. Have fun!