A trough ceramic would be ideal for that. I use one in my 6' boa's viv
The only issue is that the company that made the custom guard has now stopped trading, so you would have to come up with someone who could manufacture one.
Alternatively you could make a box structure and fit it as a shelf. You would need to ensure the mesh and construction is strong enough to withstand the weight and strength of your burm.
Crude I know... but functional
A 150w trough should be fine for your viv seeing its in a lounge