Cyclesafe

As most of you know, Schwalbe ceased making the go-to off-road touring tire, the Marathon XR (50-622). The new Schwalbe models that are promoted to replace the XR either do not come wider than 42mm or their treads don't seem aggressive enough for off-road riding.

I have a 29er hardtail with Tubus Swing and Tubus Logo racks on the front and rear, respectively. Each rack will carry as much as 25 lbs worth of panniers, gear, food, and water. I weigh 170 and my bike weighs 31 lbs. I have Sun Rhyno Lite rims, 36 Alpine spokes, and White Industries hubs.

I need durability first because I'd rather not lug a spare. Next would be a tie between weight and puncture resistance. I'm not worried about price, because, hey, getting stuck in the middle of nowhere with a failed tire would be a penalty far in excess of the cost of any tire.

Could you give me a recommendation for clincher tires for the front (>47 mm) and for the rear (<=50mm) ? Thanks in advance for your help! I asked this question in a MTB forum, but they don't apparently value durability as much as us cycle tourists.