You might look at the Roll-X from BAK. Softtop on hard cover, rolling up does not take any bed space. So far it has decent reviews. I have on e in my garage waiting for my '13 to arrive.
New Truck: 2014 F350 Lariat SCrew Shortbed, 4x4, Powerstroke
Previous Truck: 2013 F150 Lariat SCrew MaxTow HD Payload, 4x2, EcoBoost