Well, there are a couple of things to consider first off. Will this be your ONLY boa? If you don't plan to have a large collection and need to conserve space, buy the largest cage you can possibly afford for your boa's adult cage. For a male BCI, I would go with AP's T10 as a minimum but if you have room, go with the T12 or even a T20. Boas are active snakes and while they can live in smaller enclosures (again, the T10 should be the minimum for a male BCI), bigger is better.
Second, if you get a baby, it's going to need something smaller than that for a while. Boas are not Ball Pythons and do not need small, cramped spaces to feel secure, but a baby will be lost in a T10. I start babies in a 32qt tub up to 1yr old. 1-2yr olds are in a 41qt tub. At 2yrs old, they are moved to their adult enclosures.
As for brand, I love www.pvccages.com. Jim makes them complete and you can have them shipped fully assembled or broken down for simple DIY. Animal Plastics is great too and has more choices for size and you can get all the accessories (heat, light, shelf, etc) with it too. Plus I think they are very reasonably priced. I have not ordered from Proline, but I'm seriously thinking of it for my next set. I will never order from Boaphile again. Here is my experience with him. http://ball-pythons.net/forums/showt...phile+feedback. And, incidentally, I also contacted Jeff PRIOR to ordering and he was super nice - it wasn't until I placed my order that the trouble started.
Your choice really is dependant on personal preferance, but I understand your question. I like 2ft high cages because I can have a shelf in there - boas will climb if given the chance and that adds some floor space and a hiding place too. Acrylic can be harder to clean and may scratch more easily than glass, but glass is obviously more fragile so both have merits.
Good luck with your choice! Between AP or Proline, you'll be quite happy with whichever you choose!![]()