I have to put my 2 cents in about MBK's, but this is just from my personal experience:
I have kept and bred cal kings (and other snakes, lizards) for many years now with minimal problems. Last year however, I purchased a young pair of MBK's, partly because I think them absolutely beautiful, and partly because I wanted a 'change'. But I must tell you, 'change' is certainly one way of putting it, and the 'beautiful' part stops at their looks, lol. Yes, they are just as easy to care for as any Cal king or corn, but temperament-wise? LOL, My female is by far the NASTIEST little snake I have ever dealt with! She is also an escape artist, has escaped TWICE out of locked & supposedly secure containers, and as a matter of fact is STILL out from her second escape a few months ago. She has been out more than she's been in over the last year she's been here. I have never had a snake go AWOL like that for more than a day or 2, if even that. I know she's around, I just can't seem to actually come into contact with her to recapture her. And due to her supreme '[bleep]iness', this is not the type of snake I really want loose as I am due to have a baby at any time and already have a 2 year old running 'round who shows no fear of snakes at all. This snake bites repeatedly, musks, wraps, you name it. Glad I have 3 good mouser cats around. The male isn't quite as bad, at least he's never tried or succeeded in getting out (and he's kept in the exact same type of cantainer that she was), but he also has a poor attitude. Great eaters and absolutely gorgeous snakes both, but VERY bad tempered and problematic as far as handling since they've been here.
Go with a nice cal king =P But, that's just MY opinion.
Best of luck to you!

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"Klaatu...Verata...Nicht--cough, cough, cough!"