Doors for snake enclosure

I am in the design stages of building a permanent enclosure for my young Boa. It will be either 3/4" Birch plywood or 3/4" PVC. I want glass sliding doors. What kind of glass and what thickness should I go with? The enclosure will be 8 feet long by 2 feet by 2 feet out of 2 four by eight sheets. That will leave an aproximate 4 foot wide opening for the sliding glass doors. I priced out tempered and that would be $$$$ plate or laminated would be less expensive but more than I though it would be. I don't really want plexiglass or lexan as it scratches to easily.

So what are you guys using for sliders and how much did it cost?

Thanks
Mark

I will post when I get around to building it.

I just bought 1/4" annealed glass for sliding doors on my custom 3/4" plywood 4x2x3 enclosure. They cost $75 total. Tempered seemed overly cautious to me, and she doesn't have a habit of striking the glass.