+1 to what Chris says.

I lean more toward the heavy side, with a belly, and tried bibs and did not like them. For many reasons that Chris mentions, the biggest two being I felt they were too hot and just not as comfortable as cycling shorts for me. For a tour I would think bibs would be all that much more cumbersome.

I don't have any problem with shorts shifting around on me. If you do, perhaps you should give bibs a try.