Iroks or pittbull rockers. I run 37" iroks on my sami, snow and rocks. Love um. My buddy runs the pittbulls. Great tire, snow and rocks is what I've seen him wheel and they do awsome.
Ran 37" iroks, switched to 37" Pitbull Rocker (Radial) .. LOVE THEM. Also have used the Cooper STTs which are better for a Daily Driver and/or Rocks. (many guys in Utah I know run them)
But one issue with the Pitbull Rocker is road noise, and longevity. Don't expect them to last long if you DD the thing. (but from your post it sounds like you trailer, so that shouldn't be a problem!)