BTW, why are you building a turbo? Its going to cost you much more to build one instead of buying?
Never welded in your life...well good luck.You will need it. TIG welding is what you will probably need to do. TIG welding is the hardest form of welding to learn. Not to mention welding two different thicknesses of metal is a pain in the ass to do.
A good TIG welder will set you back about $1000 used, $1500-$3000 new.
I suggest you go to school if you are going to weld up a turbo kit, and then try to get your certification.
Good luck!