Glad you picked the dumerils they are great snakes! Rainbows are like other said tough to keep happy, you have to keep humidity and temps spot on or risk illness or death. They also happen to often turn into jerks as adults, even docile babies often get snappy and irritable as adults.

I agree with what has been said about ETBs, however, there are a lot of different tree boas and not all are that hard to keep. Both Haitian Tree Boas and Madagascar Tree Boas are pretty easy to keep and tend to be docile,