First off, great looking cars.
I've got my car fully equipped with the stuff from Total Control Products that FreddieCougar is pushing.
Have your friend look into that. Along with big brakes, and a Hydraboost, it's like driving a modern car in terms of handling and stopping. On an trackday a month ago, I had no problems keeping up with a Nissan Skyline.
I like your TT Cleveland idea. A Boss 429 engine won't fit between the standard Mustang shocktowers, the Boss 429 had the towers moved 1" outward on each side to make it fit.
Here's an picture of my car for inspiration...
Have a look on my
fquick site for more images.