You should go for LS V-Tec. At the right place you can get it for around $1000. then another $200 for the ecu. the drive axles,wiring, ext. ext. im sure you can get cheap at a U-Pull-It. you can get around 250-300HP out of it if you get bigger tranny, and a better head.
LS V-Tec $1000
ECU-...