Follow up information... Drewski is spot on with his ideas and that is really where I was going with this. Most of the pool contractors I have talked to and seen their work are using Jandy valves. I think the heater is a Pentar/Pentair and has about 400K BTU's. The electronic control (on your wall and in a remote) allow you to select spa heat only. This changes the valve and the spa heats up but does NOT spill into the pool when you are using it as a hottub. Your pool stays the same temp and the tub gets to 104 or whatever. When it cools down you can then cause it to "spill over" into the pool with a waterfall effect that is nice and the water in the spa is always filtered through the same process as the pool.
I like this idea so I don't have to keep up with two separate systems. I am paying big bucks for the pool to be heated and electronically controlled so I'd like to take advantage of the automation for the spa as well. HOWEVER I want the "therapeutic spa" action and most of the "spill over" spa tubs appear very simple with only 6 jets or so.
I didn't know if some of the tub manufactures that are on this forum (i.e. Hot Springs, SunDance, more) have a "inground" application as HYMBAU mentions above.
Bottom line the more research I do the more I "think" it is necessary to find an "inground" tub designed to hook to the pool heater/filter and thus using the electronic valves OR buy a separate spa and NOT hook them together. I'm not worried about dumping the hot water in the pool as you don't usually run the spill over with the heat running on the pool or spa. What I am hoping for is the ability to run the hottub year round and heat it when I want to use it but keep the pool filter/tub filter running year round to keep it clean. The extra jets and "therapeutic action" was what I was hoping to find from some of the manufactures here and get away from the basic tub offered by pool companies. If you sit in a Gunite hottub, you really just get heated up and enjoy very little therapy.
Post any links to spas that might fit the bill here. Again, all your comments are very much appreciated.
THANKS!!!
Here is on link I found with a basic (that looks like the builders grade) spill over spa and a
nicer one that is larger. This picture is the better of the two. I guess you still have to add addtional pumps to provide the action...
http://www.partypools.com/hottubs/spill-overs/index.htm