Well you should first do the intake and exhaust, following VDS Racing's topic, it's not that hard, just expensive. I can vouch also for the BMC DIA 70-130 air filter ar being the best choice (bang for the buck).
The exhaust has to be custom made, from what I saw, Vagelis from Greece used 48mm pipe for the header, you should use a 4-2-1 configuration, cylinders 2 and 4 come toghether into one pipe, cylinders 1 and 3 come toghether into another pipe, using a slightly smaller angle leaving the exahust header flange. Then the two pipes unite into one. This is kind of a replica of a Ford Escort Cossworth group A rally car exhaust header, you just have to be careful to have the right angles leaving the exhaust header, going for a longer join from 4 to 2 and from two to 1. Then you could reposition your cat or scrap it all toghether, depends on what you want from the car.
As for the ECU remap, I'll let you know more after I talk to a company that said they can do it. I'm gonna wait until I fit a belt driven compressor, and then get my ECU custom remaped by Superchips (day at the dyno).
P.S. - get some H&R -40mm spring, well worth the money, the car accelerates better and handles beautifully
10x
