I don't keep any pythons, but I have however dealt with retics & burms. I would have to recommend getting a male burm if I were you. Like other stated, retics are faster and considered smarter. However burms get quite a bit more weight on them, so both can be dangerous. Also Denial recommended 10 feet, I would however recommend 8+ due to the power of the snakes. Hope you make the right choice on whatever you decide to do, and btw if you are maybe willing to substitute, a yellow anaconda would be a great starter snake, as far as on the road to giants go.