Congrats on your (her) new pet snake.

I'd go for the AP cage if you are looking to upgrade. Keeping heat and humidity stable and correct in an all glass exo is not fun.. I use them for heavily planted terrariums with frogs and geckos, but my snakes are housed in AP cages . The PVC cage will hold heat and humidity better and will end up costing about the same as an equivalent sized exo. Plus, you won't have to modify it like you would an exo to make it work. I get the sliding glass doors, the optional door lock, heat tape, and recessed LED lighting (that option isn't on the site, you have to call and ask about it) for all my AP cages. Because I have boas and snake that climb, I usually opt for the basking shelf as well. I would not attempt a shelf in anything shorter than 15" though (all of my cages are 4'x2' x 15" tall or 18" tall).

If you are feeding frozen / thawed, you might want to consider ordering in bulk online. You can save yourself some serious money that way, but you have to consider shipping costs. I order about 6 months worth at a time, but some people order a whole years' supply. If you are interested in looking into it, check out perfect prey or big cheese rodents. Both are good suppliers with fair prices and quality packaging. If you are on the west coast, layne labs had good feeders at a good price as well.