[dadndave]

Welcome Ivan, from north of the border. I'm a bit puzzled with your wanting a cobra with creature comforts.
Air Conditioning! They don't have bloody windows.
Decent Sound System! There's only one sound you'll hear - the roar of an angry V8 ( Preferably ford - that'll start em off) coming out of twin pipes.
If you're not into manufacturing bits and spending hours constructing , also consider buying one already registered, saves a lot of hassles, and you can then add or have modified to your needs.
Definitely get up to Shelbyfest, I went last year with my son and we had a great time, with a few minor hiccups.