I am finally allowed to keep a snake, can I keep a vivarium under my bed?

[SeanF999]

I'm 22..
I'm living with my parents while at college and my mother hates snakes.
But she realised a snake made more sense than the Kimberley Rock Monitor I was planning on buying (and rearranging my entire bedroom for).

So I'm getting a snake!

I can fit a vivarium of any (realistic) size under my bed so long as it is no more than 40cm tall, with no heat lamp.

Thankfully most snakes don't seem to care for height and they're quite happy with UTHs!

The floor and bed frame are both wood, wood(heh) it be smart to put some type of heat shield between the UTH and the floor as well as the viv and the bed? It might not be 100% necessary but I'm just worried about the fire hazard.

I could fit a small enclosure on my desk, it would be no more than 2ftx1.5(or so)x however tall it needed to be if under my bed didn't suit.
But realistically I'll use that space for a small freezer for the food.
(No snakes or snake related items outside of my bedroom!)

Would this work?
I know I would ideally like the viv/tub/enclosure higher up but these are the constraints I have to work within.

Also what snake would you recommend?