IMO, if you need a DRW truck, to tow a large FW, you also need a long bed. You are likely going to carry more things with, after retiring, and going longer distances. More bed space is good, and the truck will be big either way. You will have more hitch options, not having to worry about a slider, although the rounded front of most new FWs has made that less of an issue. The longer bed will work better with add on equipment like tool boxes, or fuel tanks.
Be sure to get the FW prep option (puck system).
Welcome to the forum!
Jerry