Member PANDa!

Start with a pod filter
2nd Exhaust, free flow hopefully.
3rd Front mount intercooler. These 3 things will give you great power gains.

If your going to run the car on the track or strip then you'll need a 5speed gearbox-S14 as the 6speed is very weak.

Then you should look at the handling side.
Do it once, do it right, it'll be cheaper in the long run

HKS, Trust, Apexi, Nismo is the way to go for parts, they've been there, done it, broken it and improved it..