I just adopted my snake and I have a 20 gallon long for now. I’m running a Herpstat 2 with a UTH at 90 degrees and I just added a 100 watt CHE set at 84 degrees with the probe suction cupped 2 inches above the substrate.
I’m using a Zilla 8.5 dome light with a ceramic socket and a Flukers 100 watt CHE. My Herpstat doesn’t have any trouble keeping ambient temps at 84 degrees and the ceramic socket and light dome doesn’t get that hot at all. I have over 3/4 of the screen top blocked with a sheet of acrylic and that really helps hold heat in the enclosure. Can’t wait to get an AP tank with a radiant heat panel but this will do for now.