I run Cooper Discoverer 31 10/50's on my 1999 wrangler sport. I highly recommend these. Any tire dealer should be able to order tires with just the size and width.
You want 31X10.50X15,that is the largest tire you can fit under the Wrangler.That number has nothing to do with the tread,you will have to pick out the type of tread you want.A good all season tire would be the BF Goodrich Rugged Trail.