Mrcrowley back in the day they used to make a soft top for the bed that velcroed around the edge of the bed but if it rained on it it would sag and look like crap.
I think there's one out there that fits a Toyota that might work well but you may end up finding it's cheaper and better just to do something like we did back in the '80s which was to build a 2x4 frame, plywood top, put a little foam on top and cover it with vinyl and you could lay on it dance on it do whatever you want on it, and you can store stuff underneath it.
