CAN YOU TELL ME THE DIFERENCE AND WHITCH IS BETTER ALSO DOSE ANYONE NOW A GOOD WEB SITE TO LEARN ABOUT TURBOS AND TURBO KITS?
THANK YOU

Might want to tone down on the CAPS.. but if you search the "turbo" or "archives" sections. you should find your answers.. they might even be on the main page.
I would answer your question.. but I don't know the answer, and so I'm only trying to direct you to the proper place to find what you are looking for.

To answer your question: depends on what you want and configuration of turbo. If you really want to build a custom kit and dont know what turbo to use call turbonetics or majestic turbo or any turbo outlet and tell them your needs (top end, low end, fast spool up ect). Also depends on how you go about getting a manifold. you may have to chose whatever brand the manifold dictates (mitsu, garrett,kkk ect) and go from there on picking turbo sizes. just a few tid bits before Murix locks this one up too.

to answer your other Q T3/T4 is a garrett T3 turbine combined with a T4 compressor=faster spool up than T4 and more flow than T3 (in a nutshell anyway). 16G Mitsu turbo. many configurations of both make knowing just 16G or T3/T4 useless. T3/T4 can be built to provide anywhere from 250 to 600+hp.

I was going to leave this one.