Guys i dont toally agree with yas there... My mk4 run 225bhp and i thought the standard brakes with standard VW pads were fine and im not just saying that because i had 312mm brakes sitting in my garage ready to go on if need be.. they stopped me more than adequate from 135-140.. brake fade yer but get some uprated pads much better..
As for suspension you can get coilovers but uprated springs on uprated shocks is more than good enough and a lot of people on here run shocks and springs with great results.. coilovers are only usefull if you want to constantly raise and lower your car if your going to keep it at one height whats the point uprated shocks will me more than good enough..
I do understand that on standard suspension my mk4 was twitchy at high speeds but with no side wind ive had it to 140 without dying so they are fine to and extent..
Exhaust is a good buy i had standard cat in place but a milltek 4motion cat-back and it sounded very quiet but had a nice note to it and that also removed the mid box so less back pressure on the system..
Also a front mounted intercooler is only really necessary for stage2+ as i spoke to Nick at RTEch for ages about FMIC's on my one and he said the SMIC was fine even for stage2 its just not the best so thats worth an upgrade if going stage2 or above.. And if your going stage2 and above you will be uprated loads of bits and bobs anyways so might as well add the FMIC to the list..
Wheels and tyres is just personal preferance my standard montreal II's on decent tread done the work and gripped the road really well.. but some wider wheels would of been ideal..
Sorry if ive dragged on just wanted to let you know another opinion

Dan