The Elite essentially puts a pump and control set for the 3 major seats, rather than just one master control. What's the price difference? I personally think the sweet spot for a Captive is the 45 jet dual footblaster with ProPure, dynapoint, and 5 year warranty. Seems to me to be the best bang for buck. You should be able to get that set up for less than $11k with delivery, cover, steps, cover lift, etc. pre-tax. I've seen people getting much lower than that so you may even be able to do better, but those were fantastic deals.
The Island Spas are really awesome and a great value. I literally just talked to a customer of mine with an Antigua specc'd out like above and he was raving about how much he loves it. This is a guy who has had a top of the line Hot Spring and an expensive Cal Spa previously. All of the ones on your list are good though so I don't think you can go wrong any way.