Just and added thought...
You may want to look into several styles of martial arts to find something that is to your liking. I know your goal is to try to put some distance between you and an attacker, but it may not always be possible depending on the aggressiveness, speed, agility, and physical strength of the attacker. There are essentially two types of fighters out there - the ones who want to stand toe-to-toe trading punches/kicks, and those who want to grapple on the ground. My suggestion is find something that provides a foundation in both areas, as well as covers transitioning between the two.