Paul, Host is not building any motorized campers at this time. They do not have enough business to sustain a trained staff for the builds. I spoke to the owner 3 weeks ago. I own a 300 and am very happy with it to date. I am just not excited about Ford trucks. Our rig is 4x4, diesel and has the tow capacity you need, plus, I have the full winter package 9ie: heated tanks, electric and propane heat, dual pane windows, however to go a step further, I would talk to Kevin Erdman at Dynamax. They make a 28'er on an M22 Freightliner and they are building Super C's on the F 550 with 2 door Lariat cabs and 4x4. I have never driven the Freightliner or the Navistat so I do not know what the turning radius is on those trucks. My F 550 has the Dana 60 front axle and an amazing 60* turn radius. The turns are very tight.
One other thing, my rig is just shy of 31' bumper to bumper.