Wrong board, try 3si.org dedicated to Dodge Stealth and Mitsubishi 3000 GT. Everything you ever wanted to know about your car is over there.
But to answer your questions, on a N/A conversion, stock 9b's are good, stock 5 speeds can handle twin turbo conversions just fine, yes, there is single setups for your car.
You are also in luck, I have done more than 1 twin turbo conversion on my 3000gt, same car as your Stealth, as long as your dohc, everything from a tt bolts up, from the wire harness to the turbo manifold and turbo's to the engine, very simple swap as long as you are some what mechanically inclined.
No go to 3si.org and look in the n/a to forced induction forum, everything you need is there, stop by the classifieds and you will find everything you need, from the smallest bolt to the whole conversion. Good luck