Check out our guide to buying Infrared Saunas. There seem to be a lot of sauna suppliers around just now on the internet. A few years ago, before partnering with Clearlight, we spent a lot of time looking at just what was available before we decided on Clearlight. Not the cheapest, but but we firmly believe you get what you pay for. Clearlight were the only sauna company that were prepared to offer a lifetime guarantee and I think that fact alone speaks for itself. Check out the guide here.
Clearlight have written a fine article themselves about what to look out for, so rather than duplicate it here it is below.