I used to use the oil-filled radiator-style of heater, but recently switched to this flat-panel style.
It's like s piece of slate that has a heating element in it. I wanted something to free up some floor space. I run it through my BN-Link Heat controller.
Do an Amazon Search for:
TRUSTECH Wall Mount Heater, Heater with No Fan, 400W Convection Heater, Indoor Electric Space Heater with Overheating Safety Protection, Easy Installation Heater on Wall
That is not the one I bought, but similar.
I was worried about the backside heat, so I took an extra 4-inch booster fan and C-Clamp'd to the back side. This serves two benefits, one is that it keeps the heater 4 inches away from the tent wall, and it lightly blows some of the heat downward so that it is not all wasted away.
It works as I hope, but it is more combersome than I hoped.