Check out this
thread on this turbo kit. Also, another turbo kit thread can be found
here
Personally, I would choose the first link, the A.A.I. turbo kit, simply for the well done install, and the power put down.
But the most power on the 4G64 so far has been 316 whp and 295 lb-ft of torque. The thread for this is
here. And he is doing that on stock cams. With a new cam and valve springs, his redline will increase to 7500 RPM, and he will be able to boost even more (up to 20 psi, regulary) putting down more than 400 whp.