I am planning to get a stock xA in about a month or so, and i want to know of some performance upgrades that are available for it, i already know ably the TRD exhaust (it sucks tho) and AEM CAI. i am more wondering about headers, (custom) turbocharger, suspension, full exhaust system

sounds like a plan :) I understand that most dealers will not honor your waranty after you turbo it.