the reason so many people jump on this is because people post up expecting a list of stuff to go buy and bolt on.
well our car isnt a civic or a 240sx, therefor apart from the "pre-made" Hahn and star kits, EVERY one is a one off custom job.
everybody has different end goals and budgets. there are Too many options but they are all conected, read on

the next reason is because there is tuning required to get the 420a up to par when adding a turbo kit, some theory and background on turbochargers, fuel systems, and engine management is required.
a few months back i started to write a book about turbocharging the 420a, i realised quickly that a bullet to my head would be less painful then trying to cover every option in doing a turbo. and i realised that i kept referencing tugbocharger theory books.

Corky Bell's, Maximum Boost. avaliable at any book store as well as e-bay.

now after you read that, you will see a list start to form. now this list is VERY general and non specific.
Turbo, Wastegate, Manifold, Downpipe, Oiling supply and return, Fuel supply, etc

after you have made that generic list you can go through parts you want and fill in the blanks for what ya need / have. then the previously generic list starts to take form FOR YOUR SPECIFIC APPLICATION (Sweet huh?!) and you can also see what you need to find or make decisions about, and you can also see places where you might want to upgrade somthing.
when your done you should have a complete custom setup with the parts you need and you will know the resons why you selected those parts and how they will all go together.

now you can start posting about specific items, ie "my goal is 8psi and a DD, do you guys recomend the SMU or SFMU for my application?"
that will get you better and more specific answers (that will actually help you) from us then by saying "hey what fuel setup do i need to go turbo?"

see now thats how you turbo the 420a