I can add that there is a very friendly spa in the city (not really very far unless it's traffic time) called Ruen Orchid. You cna book on the wesbite or email for packages. Tell them you are airline. Husband and I spent 4+hours and total bill was $110(?) for scrubs, full massages, man/ped tips inclusive. It's just a lovely house off a main embassy street. They will arrange driver, too.

There is a driver we liked, Named Roong (based in Hua Hin but he does BKK too. Roong-SAYAM@hotmail.com
081-1915017 mobile Good rates good cars--it's the way to go outside the city. If you need a lcoal guide I have one--as well as licensed guide for temples etc.
If you've never been to BKK, prepare for serious stinky smog. Accor hotels have great discounts for airline under Delta codes.