couple things i wanted to point out from skimming through this thread.

Wideband o2 = definatly get one if you'll be tuning or playing with your car
EGT = get one if you plan to be pushing limits, very important, it will tell you if your motor is being stressed to much via temp.

anyone that is looking to run 15psi on stock b18b bottom end, yes, it is possible.. your going to HAVE to tune it though or it won't last long at all. Must be intercooled at 15 lbs.

i also saw someone asking what size wastegate spring to purchase, buy the smallest one avaliable, boost controler can always allow more pressure, but you can't go less.