This is the sauna that I have, it was recommended by someone in this group
http://www.qualitysaunawarehouse.com/product_view.asp?id=1504
I find it very gentle and it works very well. I installed it in our basement and my husband put it together in about 4 or 5 hours. He says it would have been faster if the basement had more floor space.
If I had to do anything different I would have found the money and space for a larger one that I could lay down in. I did buy a backrest on Amazon which helps. Without a backrest you really can't lean back which can get hard when you're in there for 30 minutes.
Best of luck in your search