Guessing you ride Glamis? Because what works for me where I dune and Glamis is completely different...A 28'' STU blaster would be a good tire since it measures closer to a 30'' than 28''. What you dont want is a tire that is to short so you are banging azz bad at full bump since the suspension was set up for a 30''+ tire.
I run the System 3 DS340 and it is a 14 paddle 31'' and works better than I could have ever dreamed for me but IMO it may be to much paddle for Glamis on a stock XX unless you have the ability to cut/trim/stagger the paddles to what would work best. If you have the money Skats are great as are Fullerton's new SandSport tires but thats if you wanna spend $1500-2000. GMZ Sand Stripper XL 10 paddle would be another tire that would work but have heard they are heavy.