as long as u use a thermostat to control it it will be ok. i would set up about a day or two before to make sure u get the bottom up to the the right temp without over heating and make sure it holds steady. i know a lot of people that setup their beardie tanks this way and the lil guys love it.

why are u using slate on the bottom of ur enclosure for ur snake? its gonna be hard to clean and it isnt really recommended. i have found that simpler is better for all involved