I know a guy who was a thirty year owner of two nearly perfect '57s. He was also the original owner of a '65 Mustang and at the time, I also owned a '65 Fastback. He let me drive one of the T-Birds. He mentioned, and after the drive I totally agreed, that, even compared to the Mustangs, the T-Birds felt really old. Of course, they are, but they seemed much more than eight years older than the Mustangs.
Now, I love what you want to do and I'm no fan of kit cars, but if I were going to do it, I'd be inclined buy one of the fiberglass T-Bird replicas and drop it over a tube chassis with independent suspension and rack and pinion.