Lots of options, got a budget? GD route, many run a mt hardtail with front sus. 2-3" wide tires are popular. Determine how wide a tire you want to run, go from there. Flat bars or drop bars? Racks or frame bags? Me? I use a Karate monkey with 29er , 2.8 ish tires, rigid fork, some frame bags and small rear rack. One could always run smaller tires with a 29er plus bike.