The cheaper route is of course the 3sgte. however the 2.2 liter motor as far as I have seen, well surpasses the 2.0 and has tons of torque when turbocharged... I have seen it done at Moroso here in Fla, and the thing not only sounded badass, but was extremely fast... I believe it was in the 11's
With that said, if u have the $$$ and the time, the 5SFE would be the wise decision, but you would need lots of engine modification, all the turbo components, larger injectors, fuel rail, a very expensive piggy back, ot a whole new EMS. Thus probably around 15-20,000.00
So there is my opinion... you could do the 3SGTE, do the slight engine modifications, upgrade the turbo and the intercooler, and recieve the same results, however you will never recieve the amount of torque as the 2.2
As much as I hate to admit it there is no replacement for displacement. Plain and simple (excluding the rotary) :0)