Turbo selection for conversion

My question is about the best sized turbos. I hear that on a FWD that the stock 9b's are on/off boost and with a huge torque gain so soon, that I'll break traction like a mofo.

So how about the 13g's? Those would be the next step up, and I assume they would work fine. I'm ok there, and have found users on 3SI who use them.

So then how about 13T's? Are they just WRX exhaust housings with a 13g inducer? How do they run in relation to the 13g's?

Next up would be the 15g's. Are they suitable for a FWD? I don't know too much about these turbos.

15T's? Another WRX exhaust housing? How are these performance wise in relation to the 15g's?

Last one..

16G's, being TD05. Are these overkill for a TT conversion? I hear they don't actually start giving power until about 4K.

These are questions I have had for months now and need a little imput from you guys. I am very confused about the 13/15T's.

This will eventually be for a daily driver/weekend car, and the cost should not be factored in. I am more concerned in how they perform on a FWD platform. Thanks in advance.

some good reading here;

http://www.stealth316.com/2-turboguide.htm

Wow that just made things a thousand times easier. Thanks bro.

What about twin scroll turbos? What does that mean? I looked it up and found no information, just people referring to them.