IMHO they suck, there was a thread on another board and they got roundly lambasted for having lame customer service, their prices are okay but it is F@!# you if you have a problem, a much better site is
mvp auto
Dusty (owner of MVP)has a supra and sells at a pretty good price and I can also vouch for his support( no finacial interest in either)
the basic upgrades are not hard a boost controler down pipe ( be careful removes the cats does NY have sniffers? ) exhaust and bcc( boost cut controler) the exhasut work can be done by any shop the electronics are not hard to install your self
check out
mkiv mirror go to the technical section they will have some DIY info the above three upgrades( ~1500.00) should yield at 18 psi about 470 hp at the crank an awesome amount of hp for a 17 yo BTW the care can be a handful in wet weather if yougo to full boost

any higher than 18 you melt your turbos some folks go single turbo for higher hp at higher $$$$ people ahve gotten 600+ hp on stock internals and pump gas
check out
north east mk oweners for info on speed shops in the nyc area good luck