"So this is a white-sided Black Rat snake, right?" Yes.

"There are also white-sided bull snakes and texas rat snakes." As well as white-sided Brooksi Kings.

"I'm curious to know where you got yours and anything you've gathered in terms of temperament and handling."

I got mine in Daytona from a smaller company that had only three of them. The other two were TINY and not very pretty. This one was seemingly healthy, nice body shape (rounded and plump) and had a perfect pattern. The woman I spoke to said they were going to be phasing them out of their collection because no one had been showing any interest in them. Apparently they were "created"? "designed"? a while back, but the general public showed no enthusiasm. The project then became known only to people with a personal interest in them - those who "just liked them". At least, that's how she explained it to me. I saw three vendors that had white-sided rats at Daytona. All three were small, private businesses. I'd rather not say how much I paid for mine (it was a good deal) but I have never seen them for less than $75. I believe that white-sided rats are the cheapest of all white-sided snakes. The kings and bull snakes at Daytona were priced at upwards of $150.

As for crossing them with corns, I read somewhere that "all rat snakes are corn snakes, but not all corn snakes are rat snakes." (I'm pretty sure that's how it went. Maybe I have it reversed.) Anyway, the thinking is that corn snakes are a wider group than most people give them credit for. "Rat snakes" and "king snakes" are arguably part of that group (depending on whom you talk to) but we've kind of "split hairs" about it and gotten more groups. Again, this is just something I read a while back. I can't even cite it, so don't take it too seriously.