Locust is a terrific wood for stuff like that! It is naturally resistant to all manner of rot and bugs, it is tough as nails, and it weathers well. The only problem is it wears out your tools, and tends to be a bit dimensionally unstable. It makes great fence posts, and truck and trailer beds.Well, after dealing with wood provided by Cranetruck, I'd be forced to send out for yellow locust for any of my projects. The stuff just about wears like iron. More than you need for troop seats but makes one heck of a truck bed floor.
-Chuck