Ive seriously considered an 89 3.2 and my own turbo setup. You get a G50 and already have a proper fuel injection manifold to start with. I'd make my own exhaust mani's anyway. Its either that or a boxster with an IMS failure for dirt money. The M96 engines aren't nearly as shitty as people think they are if certain precautions are met, and you can get a 986 down to 2500lb pretty easily.
Agreed, any g50 car is great to build, I helped a buddy with his. He's got an 88 put some stock 3.3 turbo pistons and cylinders in it, and cranked it up. It was one of the big dogs on the street down the Miami/Fl Lauderdale area back in the early 2000's. It'd still wax 90% of them the out there. Those cars have a Good engine, good trans, good axles, And hooks like a mofo