They differ from males to females but not a huge amount. I'd say a healthy adult female tab is going to be around 5 1/2 feet to 6 1/2. It seems like a big snake once they reach adults but are still very very manageable. They'll go through a small color change. You garden phases are most likely going to change the most becoming more grey/brown once they get older. As far as cage wise goes, My atbs use both high and low in there cages. Most of the time high though. Babies are all different when it comes to feeding. I've had a couple that eat like there's no tomorrow and some are impossible to get to feed. It's always a different story though.lol
As far as atb/etb hybrids I've only seen a few before. They are pretty beautiful in color but I like my snakes to be true full breeds and don't like to cross any. Hope this helps though