build your own kit, it will do 2 things. Teach you a ton and get you quality used parts for a lower cost.
As far as wastegates go, noob = internal to keep from spring miscalculations, the turbo self regulates = dummy proof.
For any boost build you need to consider the following:
Fuel
Pressure
Timing
heat
your number 1 enemy in a turbo car is detonation (google it) keeping engine temps down, your timing right and fuel amount and octane per cylinder is key (AKA a tune)
to ride on hgocasca's comment, psi is determined by turbo size. 10psi on a 13G vs 10 psi on a R35 are worlds apart.
don't worry about boost numbers, worry about hp numbers. Those are the goals you are shooting for.
My first turbo build on a B (budget build) made 225/191 on 91 octane 71 degree day and 7 psi. it never reached a A/F higher than 14.9 (sweet spot for combustion) so it was a conservative tune for daily driving. Exactly what I needed at the time.
Do your research it will help you out in the long run and will speed up the process. Check the stickies posted in the forced induction section, they will explain more than any single question you can ask.