a lot of searching and reading for starters. Decision on single or twin. A big budget, headers, intercooler, turbo(s) themselves, piping, tuning, fuel system to support it .. etc.
The power adders section of TGO is full of information from people who asked the same question.
http://www.thirdgen.org/techboard/po...ht=turbo+parts
http://www.cardomain.com/ride/764085/2