Don't rule out the Hognose snakes. They are great keepers one they get started off right and have tons of character. Plus they stay at a nice size. The Gophers are another good choice IMO. I have 2 San Diego Gopher snakes and each one has their own personality. To me they are like the Hoggies in a way they are all hiss and bluff and rarely bite (at least mine are).
The Kings are ok, but they tend musk and are too wiggly for me. Another suggestion would be a rat snake. There are tons of different species of rat snakes and not all are hissy and nippy. The Trans-Pecos rat snake is very docile as well as the Baird's rat snake. Nevertheless, do your research and balance out the "pros and cons" and pick the one that is right for you....GOOD LUCK!