BRB communal housing?

Would rainbow boas be a snake that you could house together. I have a baby in a 20 gallon long right now and i want to get another in hopes of one day breeding them.

For starters, it's never good to keep two snakes of opposing genders in the same enclosure. They will most likely breed too early and too much, compromising the health or even killing the female.
As a general rule you shouldn't keep any snake in the same enclosure. They don't like companionship, could accidently eat each other, get stressed leading to not eating, pass along sickness....and so on and so forth.
If you do decide to put two animals in the enclosure, they should be the same gender, seperated during feeding, and have a seperate enclosure in case you see signs of aggression/stress/illness....and if you have a seperate setup prepared, might as well have them seperated anyways.