for the turbo I would ask flea, he does some decent ones.... the car may need re-mapping after fitting / changing this sort of part, same goes for font mounted intercooler... this is my thoughts for getting the best out of new said parts, but others may know better.
as for the intercooler - pro alloy front mounted intercooler is good, I have got one and fitted myself about two weeks ago... for a new one is about £550.... not cheap, but get what you pay for. takes about half a day or so to fit one and some bumper modification needed. I sprayed mine black to blend it in and give stealth look rather than showing it off so much.... also I remember from physics class's that a black metal object transfers heat better than an other coloured one, white for example... not a massive amount, but every little will help I suppose... each to there own