Do you have any recommendations for where to buy or brand? My biggest fear with these is that the build quality can be all over the place and the last thing I want is to burn down the place!

I second totalZero. LOVED mine in the winter when I used to live up in the North East... nothing more comfy than to slip into a nice warm bed on a cold winter night (well, when I was single anyways lol). I've had a few different models from SunBeam, all with a timer built in to pre-heat and turn off. I found the build quality to be good, never had any issues.

I suppose there's an inherent risk, but the Sunbeam ones have an auto-off mechanism in case you forget to turn them off in the morning.