Check out the new bfg ko2
I was about to suggest that one too. BFG advertises them as having twice the treadlife on gravel and 15% longer treadlife on asphalt compared to the original KO. The only caveat to that is the KO2s are a new tire as of this fall and the 37" size only came out last month, so they really haven't been around long enough for anyone to put that claim to the test.
I am getting these in 37s fairly soon, but I picked them primarily because they're the only 37s that are winter rated. The tread life on gravel is a big plus for me though, since there are a lot of chipseal roads up here, and even the paved roads are graveled in the winter. For the OP, conditions down where you are are a lot different, so I doubt those are factors you're concerned about.