reptilebasics.com is great! they come highly recommended.
If your temp in your house is stable enough where you know a 40 watt blue bulb, for example, will keep the cool side right where you want it then there should be no problems!The other thing you can do is put the cool side bulb on a rheostat (less expensive than a thermostat) and then have the hot side UTH on the thermostat. Or, if you really wanna throw some money at it, two thermostats won't hurt (but are probably not necessary). The hot side thermo is the important one.
JonV