twin turbo Dodge Stealth/Mitsubishi 3000 GT
early 90s Camaro V8 and turbocharge it
possibly an early 90s Ford Lightning (probably not that cheap though)
any year V8 Firebird or Trans-Am
1.8 turbo Audi A4 (or any Audi/VW with this engine) and mod it (stock internals good for 600 horses, no joke)