You spend a third of your life on a mattress, don't be cheap!
King Koil is a good mattress, most of the time if you tell them your chiropractor sent you they will give you 10% off.
If you are interested in a Tempur-Pedic of a Select Comfort I can order direct through my office and get you a better price.
My next mattress will be a select comfort.
My .02 throw the water bed away, your spine will thank you later.