Ok, so you know the driver part....well obviously a year or two of working on the guy behind the wheel is good.
Otherwise, its how much ya got to spend?? I'm a fan of anyone that chooses to go their own route and develope what they got. So, for STS:

Get the engine checked out, replace all the wear items there:
All gaskets (including the head), timing belt, refresh the head maybe if ya got the time/money. My engine is at 144K (The last 30K have been to/from events, and track days), and right now I'm scrambling around hunting down leaks I never thought about when I started. Replace your pulleys with something lighter/underdrive while you are at it.

Wheels: the lightest, smallest diameter that are wide enough to support the widest tires you can find in that size...IE 15,16" by 7-7.5".

Tires: see above....something 215-225 wide, to keep up with the uber light EF HBs.

Suspension: Front and rear strut bars (skip lower tie bars not enough gain for the $), the biggest honkenest Rear sway bar you can find if its adjustable even better.

Koni yellows with GC coilovers: its been reported/understood you can maximally use 450lb/in springs on the off the shelf Koni's but a Koni sales rep claims, they can handle 550 for 2yrs. Get a complete set of the polyurethane bushings

Brakes: Some Brembo Blank rotors and Hawk HP+ pads'll work great and are reasonably cheap. Flush braking system with ATE super blue regularly and it'll be good all the time....

Intake/Header/Exhaust- whatever is out there for your application will do, I have no idea for 'Tegs.

Racing seats and a harness'll make a huge difference in your comfort at speed, but totally unnecessary...