Heating solutions

[Dorifto]

Actually, I found a decent sized heat matt: https://www.amazon.co.uk/Reptile-Vi...&hvtargid=pla-2281435177898&gad_source=1&th=1

Would just need to get a thermostat in addition.

Just use normal double sided tape to place it in one side, make sure to place the thermostat in between or on top of the heated area. In your case I'd opt for the in between option, that way you don't need to run any cable to the inside.

Just having a bit of difficulty finding heat tape, unless I'm looking at completely the wrong thing, can't seem to find many ultratherm products.

Look for heat tape, heat stripes, heat mats, depending on where you live they have different names for the same thing.

Simply choose one as the one you mentioned, a thin one, the ones that are rubberized should be avoided.