Affordable rugged tire recommendations

Hi, I'm looking for tires to put on my craftsman riding mower and before I just go out and buy something I thought I'd ask for opinions. I live out on a small ranch with a bit over 5 acres and I'm fighting to reclaim my land from the dense South Texas vegetation. It's full of cactus and a large variety of thorn bushes/trees and sharp tree stumps. I'm not worried about tearing up turf and need something that can really dig in and get great traction without going flat every time I mow. I was looking at the carlisle super lugs but they only come in a 2 ply for my tire size. The tires that came on the mower from the factory are 18x9.5-8 and 15x6-6 in the front. Any recommendations?