WOW! Good on ya, that's sounds incredibly awesome. I did a 9 month RTW trip nearly 25 years ago. Now also starting to think of travel on the other side of work and career.
Do some googling on RTW fares, I suspect there's lots of online discussion about it. When we did ours, there was a travel agent in san fran who was the expert, posted a lot, then eventually "wrote the book on it" (published a book). At the time, it was cheaper and less restrictive to do a series of one way fares, each bought at a big discount through some kind of brokerage house. May want to look into it.
We started our trip with a "coral tour" fare through Air NZ, which meant a trip from Vancouver to Auckland, with up to 3 stops on South Pacific islands. Highly recommended! We really liked Cook Islands, a windy place, with Aitutaki rated as a top world destination. The surfing was epic in Fiji too, the offshore islands seem to have lots of options for wind and clear water (Namotu being #1 on my bucket list, if you surf also). Western Samoa is a very cool place, like Hawaii 60 years ago. Tonga wasn't my favourite, I think you need to be on a boat to get the good stuff. Maybe start off in Maui to get your legs under you.
New Zealand a super windy place entirely surrounded by beaches. North part can be warm enough to not need a wetsuit. Australia has tons of options too.
Bali is a really interesting place to visit, has a kite community too, though I think it's light-ish wind.
South Africa, Madagascar, never been, sure like to go.
Canary Islands: fuerteventure means strong wind, say no more.
Azores: some day
Med: south france has some of most beautiful beaches I've seen, and it's windy. Spain too.
Portugal and Morocco: currently first on my list!
UK/Ireland: windy, but need wetsuit
Caribbean: haven't explored, but huge potential everywhere. Was briefly in Tobago, plan on going back in season (Pigeon Point).
South America: Brazil downwinders, Peru side off point breaks, rugged Chile exploring, lots there.
That adds up quick, you'll need 2 years or more.
Now, all that being said ... don't know your condition or interests, but if it was me, I'd find flat water lawn mow kiting gets pretty old pretty quick. Will need surf or new locations to mix it up, keep it interesting, or bank on needing somewhere with something else to see and do other than kiting! Take up surfing or stand up paddling to mix it up. Plus, sad to say, I am getting those repetitive strain injuries now, elbows, heels, hips, etc, where I don't think I can actually handle kiting without building in some breaks. Or maybe with day after day of time to fill, I finally take up yoga and cross training to try and regain that 30-something form. Plus in the free time learn to play guitar and speak 2-3 more languages. Oh man, I better buy a lottery ticket, need to start this sooner than later. Super exciting to think about such adventures.