first problem IR gun can measure only surfaces not air. They also are totally unreliable measuring anything that is reflective or shiny.
I'd say the UTH is too small it is the 4x5 inch one right and only 4 watts? I'd go with the bigger one, designed for the 10gal tank. You also as mentioned need a thermostat or at the very least a rheostat. hydrofarms are ok I am in the process of testing them. So far they are ok but not great you get what you pay for.
You really need:
2 hides not just one
a thermometer ideally an IR gun and a probed one.
Hygrometer, one from a cigar humidor works really well but I am super fussy with instruments.
T-stat (proportional is the most versatile type<herpstat, helix, ve> On/off type <hydrofarm, johnson, ranco>
Or at least a rheostat they work great in stable room temps but not so well in variable room temps.
Read over a few care sheets more than one there are a lot of variations.
http://www.vpi.com/publications/the_...hon_care_sheet
http://www.theurbanpython.com/caring-ball-python
there are lots of other ones out there read a few.