I try to NOT order anything online, but I guess I'm lucky in that I can usually order from my dealer. However, that sometimes doesn't work as expected. THEY ordered sand tires and rims for my quad from ITP... What arrived was the wrong size tire, wrong rim (8") and with wrong lug pattern. What was great, I refused the parts (naturally) and they had any headache sending them back.
I have had good luck with getting my Razr 22x10x11 and Razr2 21x7x10 from rockymountainatv... The right tires came and on time.