I moded a tank so that it would be half water and half land for my pair. Cleaning the water is the only tough part, though a filter helps a ton. The snakes seem to really enjoy it, more so than before I made the tank semi-aquatic. I just used a piece of plexi-glass, at about a 45 degree angle. I sealed it with aquarium sealer, and decorated it with smooth river rocks. Their light is oriented above the river rocks and to one side a bit, so they have a great basking spot. They spend part of the day basking and hiding, the rest is spent swimming around and climbing over their features.
I haven't tried live plants yet, but I do have fake grass, some large leafed fake plants, and some plant/rock features in the water for them to enjoy. The fake plants take less work, stand up to my big female climbing on them, and don't die on me. XD

As far as substrate, I used lava rock on the bottom of the land side, then reptibark, then a blend of bark and cocofiber soil, then some moss around the plants and in the crevices of the rocks to keep things from getting too messy. So far I haven't had any fungus problems, and they don't dig much outside of their hide. I have gravel and river rock on the water side to try to encourage good bacteria and give them something to have to hunt around when I give them live fish.

Good luck on your project! I love tanks like this- natural looking, snake friendly, and easy to care for.