a new turbo and remapping the ECU is gonna give you a lot of hastle. you'll have to dyno that thing quite a bit to tune in the timing and mixtures. those things don't just come plug and play, even when they're sold as a package (such as stage 1). any good tuner will tell you that you'll have to put dyno time in when you do something like that cuz every car is different. and what about suspension? i know the suspension is already great, but if the power isn't enough for you, then you're probably gonna want to lower and stiffen the car too. this will cost extra money. just chiming in.
-moldy