5th wheel weights vs tongue.

Unfortunately the 1600+lbs for payload is the limiting factor. 5th wheels carry the bulk of their cargo in front of the axles. That just adds more to the trucks weight. About the lowest pin you can get on a smaller 5th wheel is around 1000lbs. You could go with an Anderson Ultimate 5th wheel hitch. IIRC they weigh around 100lbs including bed rails. If you load light it's barely doable. But IMO doable since you say you travel alone. Throw some E rated or D rated tires on for insurance.
http://www.palominorv.com/productinfo.aspx?model=puma&page=floorplandetails&floorplanid=3945&RVType=FW


http://www.palominorv.com/ProductInfo.aspx?
model=sabresil&page=floorplandetails&floorplanid=4308&RVType=FW

http://www.crossroadsrv.com/cruiser-aire/floorplans/item/2014-caf27rl?category_id=89