Hi Twiggy, and welcome to the forum. My short list of some I would take a look at in no particular order would be:
Arctic Spas
Jacuzzi
Sundance
Hot Spring
D1
Marquis
Some others I wouldn’t rule out would be Artesian and Clearwater Spas.
I would look at some of those online first to find some local dealers, then go out to the stores to get a feel for the dealers themselves. Buying from a good local reputable dealer can be just as important decision as the tub itself. Many will recommend picking out three or four and then go wet test those spas to help make the decision. Lastly, with the price range you have in mind, you should be able to purchase a very nice quality spa from any of the manufactures listed above. Good luck!
Thanks I am doing exactly as you said and will wet test 3 - hopefully then the decision will be easy.