Build planning for 6x2x4 and 6x2x2

[Starscream]

So I've been planning for a future snake that I won't even have for at least a year, maybe more (Russian rat snake). I've also been looking into wood aquarium builds because I kind of want its adult enclosure to be a paludarium with a river-like water feature, though I have plenty of time (years, in fact) to figure that detail out.

For the Russian, I'm wanting a 6Lx2Wx4H, because they make great display animals and love climbing, and I'm thinking that I'll be able to make it out of birch plywood. Just looking at the prices of 1/2"x4'x8' ($37) and 3/4"x4'x8' ($50) birch boards at Home Depot, this is exponentially cheaper than a PVC enclosure, and from the build videos I've been watching, it's easy enough to waterproof and seal plywood, so long as you use the correct animal-safe materials (pond armor, silicone that's not mold resistant, etc). From my rough math, I'd need at least 3 of these plywood boards. I'm wondering which thickness would be better? Is it necessary to use the 3/4", or would the 1/2" work? I'm sure I'll have to use pieces for some support on the back part, since it'll be the one that's 6Lx4H.

The front's going to be two glass pieces for doors, and a smaller strip of glass that runs the entire length of the enclosure to hold in substrate and water, but as of yet I haven't decided how high I want it. That strip will be sealed in using silicone. I also haven't decided if I want these doors sliding or hinged. I'm wondering if putting half a screen top for this one is a good idea, as Russians don't need that high humidity, but supposedly love water. The other half of the top would house the RHP. There'd probably be another vent hole down near the water/ground level, on the hot side, to give a more natural air circulation to the cage.

But all this looking into plywood and glass prices made me realize that not only would this project be cheaper than buying a PVC enclosure, that doing one for my ball python would be cheaper, as well. I'm wanting that one to be a 6Lx2Wx2H, with at least a 6" glass or acrylic strip for substrate, and sliding doors. I'm wondering if I can buy a glass aquarium second-hand off someone cheap that's got the right door-glass dimensions, though it looks like most 36-inch-long tanks only go up to 18 inches in height. I might do a 3-inch border around the front, so that would maybe (?) work.

Only problem is, I have no building experience, nor access to tools (yet). And I'm in no hurry to build either enclosure, as I wasn't planning to get an AP cage for Maze for a couple years, anyways, and the Russian's I wouldn't really be worried about until 4 years from now, either. Only point in my favor is I'm really good with my hands, and have used some wood-working machinery before, though only for art projects.

Just thinking into the ether, apparently. I like having a rough idea what I'm doing before I jump into things. Any suggestions/concerns?