Check out top manufacture's websites and look for local dealers. Schedule a wet-test and see how it feels under the water. Not all tubs are built the same, jet pressure is very subjective and numbers don't tell the whole story.
Once you find a local dealer - look up their reviews as the dealer is your point of contact for all warranty service (they are the ones covering labor costs for service). The dealer you buy from is almost as important as the brand you buy, so be sure to research the dealer extensively and review customer feedback online.
Last thing to note - not all tubs are built to last the same lifespan. Extremely low budget tubs might only last 5 or 6 years before the frame rusts or jets start to leak. The average tub seems to last between 8-15 years with proper care/maintenance (that's filled/running the whole time, properly maintained and water always balanced). Top of the line flagship spas from the top brands might be built to last 20+ years with proper care. Most brands offer multiple product tiers to fit everyone's budget, just know that not all of these product tiers are simple bells/whistle upgrades, but sometimes improvements are under the hood to increase lifespan - I always like to look at marketing materials from the manufacturer and see what differences they have between their top end models and the bottom end models - what features do they promote in the top tier, and what do they advertise by comparison in the lower end models?
Personally after waiting twenty years to research and buy my first spa, I realized the nicest tubs I wanted were WAY more expensive than I expected. Since it's just the wife and I with nobody else living in the home, I opted to get the nicest 3-seater I could buy as opposed to the largest tub my money could afford. I ended my search with a 2019 Hotspring Jetsetter so naturally I tend to be a Hotspring fanboy, but they are not the only good brand on the market.
