You won'r go wrong with a Hot Spring, Sundance, Marquis, or D-1. Some D-1 modela to consider would be:
Aurora II
Chairman II
2005 Californian
Diplomat
@Home Hot Tub Series:
Dream HP
Sojourn HP
Venture
That should give you a good start. And Definilty wet test them.
Jason,
Store manager for a D-1 & Caldera Dealer