I am in the process of building melamine cages as well. 6 48x24x12 and 2 24x20x24. I am using radiant heat panels. I should have them done in the next week, just waiting for the glass to come in.
I do not forsee any issues with this set up but I will let you know if there are. I know some don't like melamine but my buddy built many gages out of it when he had his pet shop years ago and had zero issues with it. Just make sure you seal it well (I use dap 3.0, it remains flexible and does not shrink), use an absorbant bedding and spill proof bowls. As long as you don't have standing water on it, swelling is not an issue.