Unless your extremely mechanically inclined (ie., can do all the work yourself) i would avoid that one. To have it fixed by a professional, your looking at probably $10000...it which case, you can find one in exellent shape instead. One thing about the VR4 and Stealth TT is that, though parts are expensive, the labor cost is what will really hurt you.
Mitsubishi advertised about 300hp stock and 325lbs of torque if memory serves...but that can be increased significantly (500+) by a few fairly easy mods. Not sure what size the turbos are, but it runs 14psi stock. 0-60 is under 6 sec and top speed is electronically limited to 155mph. Ive heard a few boasts that it will do 175 with a new comp. though...
BTW, its a 3.0 liter TwinTurbo V6, AWD
other possible options:
AWS
Active Exhaust
Active Aero
Active Electronically Controlled Suspension (ECS)
a few good sited for more info:
www.3sxperformance.com
www.3si.org
www.vr4stealth.com