well here is my question, have you kept snakes before? Are you prepared for a snake that could be hunger aggressive or be aggressive to you once pulled out of a cage?
I own a few Kings and a couple of mine are aggressive.
I think that's a bit unfair... heck, most the corns I kept are way more aggressive feeders or aggressive in general than the L.Mexicana kingsnakes for instance. I have been bitten by a corn, never by an L.Mexicana though.
It's a huge family with many species, each of which is very different from one another, be it the Getula, Triangulum, Mexicana and many many more.
As for your research... google for the terms: Milksnakes, Lampropeltis, Lampropeltis mexicana, Lampropeltis getula, California kingsnakes, Mexican Black Kingsnakes, Prairie Kingsnakes, Arizona mountain kingsnakes, Thayeri kingsnake, Durango Kingsnake, Graybanded Kingsnake and there are many more...
The best way to go is just learn as many names as you can, find a species you like and than focus on it. It's a bit like saying you want to keep a dog- it's race says a whole deal about his character. Same goes here.
My personal favorite colubrids are from the L.Mexicana complex.