the biggest thing is that you get some kind of controller, regardless of that kind of UTH you get. that i can recall, i don't remember hearing of any UTH's screwing up, just the cheaper thermostats. even then, i've read about many people having luck with the off brands. my personal view- buy the good stuff first. if you have any questions on what size heaters to use, i would contact Rich with Reptile Basics. i know hes helped a lot of people with their set ups, myself included.