I would go with AP T8 all the way. They are by far the most reasonably priced and quality cages you will find. Super easy to put together, and their customer service is known to be great. I personally do not give climbing space to my snakes, but that is also a consequence of the number of animals that i have. I simply do not have the space to warrant climbing space. All my boas are happy and healthy without it. Others on here like you have seen allow their animals to climb, which is great, just not my system.