I was wondering if anyone has put the Porsche Brakes (Caliper and Disc's) along with a Turbo Twist wheel on a 89 Iroc? If not the brakes, then what about just thr wheels?

The Porsche wheels have massive offset/backspacing. You'd need monster spacers/adapters to mount them.

As far as performance, when looking at wheels and tires there are three areas that come into play: contact area, gearing, and weight.