turbo 5.3

what turbo do i use were can i get the setup and the cheapest how much power am i going to get or should i just supercharged

Proceed with caution.
It may be illegal for street use if you change it over.

http://www.epa.gov/air/caa/caa203.txt

STS turbos.... www.ststurbo.com

The differance in power for Turbo vs Supercharger is that you will get instant power with a supercharger. A turbo charger has to wind up with the exhaust.
Go with a Supercharger they are a little more expensive, but better gains.

While yes most turbos need to spool before full boost. The STS is still a turbo, but sligtly oversized due to the fact that its rear mounted and they use larger tubing to compensate. STS turbos make full boost below 3000rpm. Also with the STS, since its rear mounted you do not need an intercooler (its not taking air from under the hood). Other plus of the turbo is no parasitic power loss. And although it has no performance function, the sound of the blow off valve is always cool. Also look at www.nelsonperformance.com he has a STS turbo Avalanche. Pics and videos. Im planning on a STS turbo later this year, or waiting for the new GM light duty diesel to put in what has become my project truck.