270 lbs on a bike that can handle 2-up riding won't be an issue at all.
Those that are made for single rider, usually have plenty of power to haul around a few more pounds.
6 feet may mean the Ducs (and many sporty bikes) are becoming cramped.
Try them out and see what bike fits you.
A Hypermotard or Multistrada won't have much problems with you
The sportier the bike, the more of a squeeze it'll be.