I will start by saying that I not have an R1 raptor but have raced a few and have read everything I could find on the subject before I bought my tires. I have a ZX14 powered raptor. From what I read from other R1 members on the forum the best paddles they found were the 10 or 12 paddle skat trak extremes or haulers, I believe 22" with rollout around 72". If you decide to go that route I have a set of 22/11/9 haulers 12 paddle triple buffs with raptor bolt pattern that I will be selling. I tried the 10 paddles, not enough, and the 12 paddles are not enough for my torque and weight.
I know a lot of people have posted that the R1's post big hp numbers but they do lack torque in comparison to the 1300 plus cc motors like the hayabusa and zx14. It seems the R1's really need to get waaaay up in the rpms to find their power. That is why I wouldn't go much more than the 12 paddles. Your 55 tooth sprocket is a good choice in my opinion, but I run a 60 tooth so I make a boatload of torque. I know at least 2 other R1 members here tried some 24" 14 paddles and sold them to go back down to the 22" 12 paddles. Of course your swingarm length, and the type of sand and dampness of the sand all matter as well. Realistically, a person could justify 3 different sets of paddles to optimize a quads performance such as yours. (Good luck getting the wife to sign off on that purchase).
Congrats on the quad, what I have found is that you won't be the fastest, as I am not either, but dam it is fun when the power rolls in and you hook up. Can you say "Roost!!!" Those dam built banshees are light and quick, but they don't go riding out in the dunes, just live 300ft at a time. I don't know if yours is set up for duning but I drive mine everywhere, gravel roads, trails, dunes and drags. Don't get me wrong I don't trail very fast and only on my groomed trails. But nobody wants a piece of my ass in a race across the hayfield or down the gravel road. Enjoy