Let the car pick you.....
that is what happens in soviet russia, the car picks you!
OP the range of cars you picked are my favorites. i own a 66 c code coupe. best advice i can give you is start by finding a mustang in decent condition that runs good enough to drive daily. if you prefer convertibles, then buy one you like, if you like fastbacks or coupes then the same thing. if it doesnt matter then buy the best car you can afford, that you like.
remember to check it over carefully for the typical mustang rust issues, especially cowl rust issues. once you have the car, start by driving it around and get used to the car before you start making a plan for the car. this assumes it is in proper condition for driving, Ie the brakes work like they should, it has god tires on it, the
suspension is in good working order, etc.
once you have driven it for about a week or so, you can start to plan what changes you want to make. things like adding chassis stiffening, rebuild/upgrade the
suspension, brakes, etc. do these upgrades on weekends, s that you can have the car to drive during the week t keep your enthusiasm up for the car.