Definitely looks like a hypo boa constrictor, either a really clean hypo or it could have another morph in it (I'm not too good with morphs). Enclosure should be Length+Width, so if your male gets over 6' you may want to consider stepping up from a 4'x2', and of course that's just the minimum! You can go as big as you want, just make sure to provide cover.

I too love the boa constrictor's feeding response. Mine has never missed a meal except for a period in which I was accidentally feeding much too large of prey, but he went back to his ravenous self once I started offering smaller prey again.