I appreciate all of the replies - some good information and suggestions. I decided against the Hydrospa after looking at a used tub that was in the classifieds this weekend. I bought a BullFrog 552, about 1.5 yrs old, for $3500 from the original owner. By coincidence I had actually stopped by the Bullfrog dealer the day before and looked at that same model. Seemed to be destiny that it was in the paper the next morning. Anyway, at less than half of what the dealer was asking for a new one, figured it was a decent deal. Looks like it's been taken care of and the owner seemed considerably more trustworthy than the majority of dealers I've met (no offense intended). Now I have to figure out how to get it to my house;-)
Thanks again! As a newbie, I'm sure I'll be posting more questions soon regarding electrical connection, chemistry, etc.
Mike