Glass tanks are actually just as easy to keep up with a few tricks. Have you foil treated the screen? If not, that is a major contributor to loss of heat and humidity. I have a pic step by step I can PM you if you like.

Also, insulating the back and sides of a glass tank is essential for steady temps as well as snake security.

If you still wish to get a display cage, tho, I also recommend the Reptile Basics cages, and Animal Plastics second (tho you have to assemble those and heat costs extra).