I haven't built a monitor cage, yet, but I'll be building a temporary one several months from now & I've thought a little about some of the things you're asking about.
What size cage are you thinking of building? Some people build lifetime cages that are just about size of a room or bigger, complete with 2x4 stud walls, ceiling, regular door and a large window.
If you're not building a room-sized cage, you could use plywood, MDF or melamine for the main material and use formica, FRP, or something silmilar to protect the bottom and lower parts of the walls. If you used some type of clear coating for protection you could find yourself doing a lot of touch-ups or re-coating from the monitor's digging.
I think you should stay away from using any plastic or synthetic windows, like: lexan, acrylic, etc..., due to how easy they are to get scratches from the monitor and/or cleaning.
As mentioned earlier, you can either order the track online and have the glass cut by a local glass shop or just get both the track & glass from the glass shop.
As for logs and limbs, sometimes they can be found at reptile shows, pet stores, etc... I've used driftwood that I found on lake shores. Some hobby/craft places carry these, too.
If the wood is small enough it can be placed in the oven to kill anything on it. For larger pieces I spray heavily with a mixture of about 5% bleach, 95% water, let it dry out and repeat the process several times over the course of about 2 weeks. Some mite-killing formulas might could be used, too, but I'd use something that was approved for reptiles.
This is just my 2-cents worth. I hope it will at least give you some ideas.
Take care!
Mike
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