Kanati Mongrels on my 900XP?

Hey all,
The tires on my 2011 900XP are shot. I currently have the stock ITP XCT Tires on there. I live in CO and usually do typical Colorado style trails (Rainbow falls, Central City, Kelly Flats etc) with not much mud. I will make the occasional trip to Moab. I was looking at the Kanati Mongrels in size 27x9R12 and 27x11R12.

Who else is running these?
Are those the best sizes for my stock 900XP?
Opinions?
Best place to buy?

Thanks,
Seth