8 vs 10 really comes down to personal preference. A 10" wide wheel will make those tires look really wide. If you will be in the sand a lot, where flotation is important, it might work better for you than a 8" wide wheel. What was mentioned before is true as well. If you want to do some wheeling with the tires at low pressure (10 psi) the 8" wide wheel will hold the beads better.
If you want the wide tire look, go 10"