I have an insulated room just shy of 10x10 ft. I purchased a small ceramic element space heater for around $25 (if that). I run it on its half-wattage setting of 700 Watts, and it heats the room nicely.

Most of the small space heaters are ceramic element - basically a CHE and a fan. They are very quiet and really do a nice job.

The best space heaters for herp rooms are probably the oil-filled radiator types due to their efficiency, but even a small oil-filled radiator space heater is probably too much heater for your room. I would stick to the ceramic heater.

My advice is to wire the space heater into an ON/OFF controller rated for 1500 Watts at least. Ranco and Johnson are both good models for the thermostat. Do this for two reasons. #1 is for the added safety of a 2nd thermostat, and #2 is that the Ranco or Johnson sensor can be located where you want to sense the room temp. The T-stat on the heater only senses near the heater, not at the other end of the room.
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Mark