In my t10s I have 80watt rhp (reptile basics). I dont have a UTH though. The 80 watt is mounted on one side of the top with the probe stuffed through the back middle vent about 2/3 down.The thermostat is set for 84 I think, I just adjusted it till I got the temps I wanted.. It keeps the cool side at 80 and a shelf under the RHP stays around 86-88 for a basking area.
I was a bit disappointed that the 80wt didnt give me a warmer basking area and without a shelf there wouldnt be one at all. However my boas never bask, ever.
I have a 40wt in the t8 for the bp and it works perfect without a uth.
We shall see how it goes this winter when the temps get colder.