Either of those would be great for an adult ball python. I would not recommend an aquarium for the following reasons:
1. Glass is extremely heavy, especially with substrate in it.
2. If you go with the glass aquarium you will likely either need a custom lid or have to foil/wrap a portion of it to keep in humidity. Glass itself holds humidity fine, but few commercial terrariums come with humidity appropriate lids.
3. Glass has a higher thermal conductivity, which makes it a poorer insulator than plastic. Also, the plastic in the above enclosures is much thicker than aquarium glass so, in short, keeping in heat is much easier with thick plastic.
Are there any cheaper options for an enclosure like this? I can drop $250 on it if I have to, but I would prefer not to if it isn't necessary.