what size zoomed UTH would you use with a 32 qt tub? Also I noticed they have a rainforest and a desert UTH. Does it matter which one you use if you have it monitored with a thermostat?

I saw on the baby python setup sticky that they covered the bottom of the tank with foil to spread the heat and didn't put the UTH on the tank, just set it underneath it. Would this work for tubs as well? Thanks, I am also setting up my first tub in hopes of picking up another snake soon.