I think that your idea of possibly owning a pine or other pit is a great one!
I kept kings, milks, and corns for a long time but pits drastically changed my hobby.
Their temperment can vary and although they are known for being hissy with some individuals, I have never experienced such calm snakes that have been such a joy to handle. My faves are northern pines. The ones I have love to be handled, even for hours, and that goes for my bulls as well.
They are larger than the other colubrids, but do tolerate cooler temps. I keep mine anywhere from 76-80.
As far as what kind is the best to have, I of course would say any but look at as much as you can and see what strikes ya! I would say have at least one of each ( bull, pine, and gopher )in your collection! Then just watch the pit amount grow! You can't have just one!
Keep us posted with what you decide to get!!!

Take care!
Billy
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Genesis 1:1