I have a pre-wired Johnson Controls A419 thermostat I got from Reptile Basics. I've had no issues with it. Surprisingly, at least for me, the Zoomed UTH's and Flexwatt put out the same heat/wattage ratio so I have them all hooked up to it.

I also have a 40 Breeder and unless your ambient room temps are greater than 78 degrees you will need the lamp (low watt bulb) to keep the cool side warm enough.