I'm not an expert, and I have very (read: almost NONE) limited knowledge on venomous. The gaboon/rhino hybrids I've seen are very pretty, but I've heard they have problems with their head structures? Something about how the head shapes vs body shapes are different enough that not all of them work out very well.
Any info would be appreciated!
As to your question, my feeling is why not? As long as they're sold as what they are, I don't think there should be a problem. They end up fairly nice, and I don't see it as very different from breeding different morphs. Why would you want to represent an albino boa as a normal?