If you do go palludarium, I was thinking something with minimal horizontal space, mostly just a really shallow backdrop, with vines/wood throughout, and the occasional shelf. there are plenty of viv/paludarium plants that you could grow just off of treefern/corkbark/whatever.
If you put terrestrial critters in there, they would almost have to be arborial/climbers due to lack of horizontal space.
or you could get tricky and put a dry shelf on the middle third, have a waterfall/feature on one end, the water flows under the shelf, and then have a pump uptake on the other end.
might be too problematic on a tank that deep, it would be near impossible to reach under the shelf if it wasn't removeable.