Those should be great for your intended purpose. I'd go with the WR38 for the wider internal width, but that's me. FWIW, I've got two sets of carbon wheels nearly identical in build from BTLOS and Nextie built up with Sapim CX Ray spokes and straight pull DT350's that I use for both road and gravel (Conti GP5k TL for road) various WTB tires for gravel and both have been bulletproof. I'd expect the same from an LB build.