As has been said, tree boas/pythons are mainly just display animals. They are fragile and usually have nasty temperaments. I've got a couple atbs and let me tell you, they live up to their reputation as jerks. Most of them require far more work than most snakes.

Carpets might suit your needs if you want something that can be handled and are easy to care for (similar to a ball python in most respects). The downside is that as they get older they usually become more terrestrial. However, my IJ is an adult and she spends 80% of her time perched. Others I have had were more like 20% perched, 80% terrestrial.

Others to consider would be Asian vine snakes (although they are rear fanged), rough green snakes and Indonesian tree boas.