Most hot tub/spa dealers offer models from a number of manufacturers, but limited space necessitates a limited number of models in the show room. Also, some dealers get better deals from certain manufacturers (kickbacks, etc.), so they choose to carry specific brands and models mainly for reasons of profit rather than which models may or may not be the best for the consumer.
Though you might be able to find a hot tub that suits your needs just by browsing a number of dealers in your area, if you have specific features you are looking for, you might have better luck figuring out which manufacturers have the features you want in the price range you want. Then, you can find out from the manufacturer which dealers carry their hot tubs. Since many manufacturers have patented jet and seat configurations, you will find that there is a surprising amount of difference from spa to spa. That's one of the reasons
it is a good idea to try a number of different models and manufacturers before you decide to buy.
In order to help you find the features you are looking for, I've put together some statistics (i.e. special features, models, price range) on a number of the larger spa manufacturers. (The information is accurate as of 2005.)
Hot Tub & Spa Manufacturers List
880 Series, 850 Series, 850E Series, 780 Series
Fluidix jets, MicroClean and MicroClean II filtration systems, DVD player with pop-up speakers, optional remote controls, optional LED lighting, aromatherapy.
Jacuzzi Hot Tubs
300 Series, 200 Series
"PowerPro" jets with 50/50 air-to-water ratio, LED-backlit "Water Rainbow" adjustable waterfall
Hot Spring Spas
Vista, Envoy, Vanguard, Sovereign, Accolade, Prodigy, jetsetter, Grandee
"Luminescence" LED light system, "SpAudio" music system, "BellaFontana" water feature, "Wellspring" water feature
Master Spas Legend Series, Down East
15 inch pop-up flat screen TV, speakers, stereo, LED lighting, DVD
Dimension One Spas
Bay Collection, Aquatic Fitness Systems, Reflections, @home Hot Tubs
Patented curvilinear design, NeckFlex jet pillows, dynamic massage sequencer
Source: America's Top Hot Tubs & Spas 2005 edition