oh..sorry..my mistake for not knowing that u already hv ATF cooler.
your aim was to have a bit power. if i were u..i would do the basic things first.
by anymeans..Turbocharged engine is a really hot...
Cool the incoming air - Compressing air raises its temperature. However, you would like to have the coolest air possible in the cylinder because the hotter the air is, the less it will expand when combustion takes place. this why the purpose of intercooler for turbocharged and supercharged are made for..
so having said that..
u can start by doing a cold air intake and upgrade your intercooler size (i'm assuming your are using OEM RVR intercooler) don't go to big.
Let air come in more easily - As a piston moves down in the intake stroke, air resistance can rob power from the engine. Some newer cars used polished intake manifolds to eliminate air resistance Bigger air filters can also improve air flow. its easier to say that porting and polished your engine head, intake manifold will help.
Let exhaust exit more easily - If the exhaust pipe is too small or the muffler has a lot of air resistance, this can cause back-pressure, which has the same effect. High-performance exhaust systems use headers, big tail pipes and free-flowing mufflers to eliminate back-pressure in the exhaust system.
those mention above are the basics. the engine management should be the last thing that u should add..after u are satisfied and have no other near future plans.. wont want to be tune and tune and tune again everytime u mod ur engine didn't u?
as for wastegate and boost controller..from my opinion those are not basics.