Thanks. I appreciate all the valuable advice given in this forum. I found some plain mylar for $12 a yard, so I figure it can't hurt and it might help.
After researching spas in this forum and the pool+spa forum and seeing what was available in our area we narrowed it down to a Sundance and a Marquis. Since we have limited space, we were looking at the triangular tubs that hold about 150 gallons. After trying them out, we found the Marquis Rendezvous was a good fit. Also cost $1000 less!