I'm Planning on doing in the near future: Turbo Upgrade, STi Intercoler, Unichip engine management system, Turbo Back (Quite as I can find) Stealth Twin Tip Exhaust Upgrade. Balance Engine Manifold to balance temps and pressure on the boxter 4-cyn. Complete Dirt driving Pacage --> Mud Flaps, Skid plates and diff covers.
Finally my last thing is to get a Steel Cage for Racing Belts and maybe even a full roll bar system Certified by applicable Rally Circuit.
Okay well then...
Yeah i full expected Turbo upgrade NOS, you name it. You have a good start but Caps (Silver and Red) wire management, 12v line with Fuse for Rear Sub Amp (Alpine V12), is very basic. CAI isnt bad but not really good on a close to stock car. Engine mounts are a great start! and strut tower braces.
I dont think you want a unichip (old and not made anymore). Do you mean Balance engine manifold = equal length header? pros and cons to that too.
Start with the stickies on the boards like: Engine Performance FAQ [[[READ ME]]]
Looks like you really need to ask alot of questions and read some more... But great start!
Here is a list of my car and I'm only stage 2.
Engine Mods: Custom Grounding Mod, Gruppe-s Turbo Heat Shield, ECUtek Reflash (Kingpin tuned), K&N Drop-in Filter, Bosal Divorced Waste Gate Down Pipe, Helix Flex Up Pipe, Greddy EVO2 Catback, Silencer Elbow Delete
Suspension & Drivetrain: 24mm Whiteline Rear Sway Bar, Whiteline Heavy Duty RSB Mounts, Perrin Rear Endlinks, Front Strut Tower Bar, Rear Strut Tower Bar, H-brace
Exterior: Limo Tint 5%, Debadged Rear Hatch, Steel Grey Rota Torques w/ 235/40-17 tires
Interior: Autometer Dual Pod Bezel, Autometer Sport-Comp Boost Gauge, Autometer Sport-Comp Voltmeter Gauge, MOMO Shift Knob, Forester Din Pocket, Armrest Extension, Matching WRB Child Car Seat, JDM Broadway Mirror
Audio & Entertainment: Kenwood KDC-MP828 Head Unit, Kenwood SIR-KEN1 Sirius Module, Rockford Fosgate Punch 100dsm Amplifier, Pioneer TS-W256C 10" SVC Subwoofer, Custom 10" Subwoofer Box