The ventilation is gonna need to be adjusted as you go. Just start with a few of why at all.
You certainly can use a mat but it is not going to be a simple plug and play procedure. The uth needs to be kept from direct contact of the snake. You don't want urine and other fluids on it.
Also a uth is not going to do anything for your air temp.
Depending on the height of the enclosure a radiant heat panel may be a good option. They seem to work well in wood enclosure as the wood holds the heat well.