I am about to buy a 2001 or 2002 S4 and I want to do exhaust/intake/ecm/turbo upgrade pretty much immedietley. From searching around the K04 turbo upgrade seems the most popular way to go and get in the area of 420hp/450tp with what i want to do. Is this really the best way to go? What is everything ill need, besides the turbos themselves, and where is the best place to buy it all? About how much do they run?

Thanks in advance for any advice!