I did some research and of course everyone says their heater is the best. I did find some information about the carbon heater emitting some type of fumes. I have my eye on the SaunaRay http://www.saunaray.com
They do charge you for shipping, something that most companies don't but this is the only company that uses Basswood from Canada and the ceramic heater.
Right now with the way the economy is I just don't want to spend $3,500 for a sauna.