With that money I'd do a significant departure from established mods. Here's what I dream of:
1. Bored/Stroked 3.5l H-6
2. 11:1 compression custom pistons w/Deves rings
3. Chrome-molly rods
4. Stage 2 cam regrind
5. Upgraded valvetrain including competition valves, HD dual valve springs, aluminum retainers, ss seats
6. High strength main studs, rod bolts, head studs
7. Light to moderate port/polish on the head
8. Copper head gaskets
9. STi 6-speed conversion
10. CAI
11. Custom exhaust, 2.5" off the headers and 3" cat-back.
12. 150 shot of nitrous
13. To control it all a Simple Digital Systems (SDS)
EM4-6F. This means dumping the stock ecu/tcu and and having full controll of you entire engine map setup.
Of course I'd want to make it stop and handle well first but that's the easy part.
Oh yeah, it would need a kick-ass stereo and a custom paint job too.