I'm doing what you want:
2013 Jayco 26.5 RLS, 2012 F-150 Ecoboost
Just got done with a 4,100 mi. trip - Minnesota to Worcester, MA to Bar Harbor, ME and back.
You must get the Max Payload package, in addition to the Max Tow package to be able to handle the pin weight. Apparently many dealers don't realize they are seperate. Mine ended up with a second truck to sell because he didn't know. Check and double check. This means you will also have to get the SuperCrew version - Max Payload not available in the shortest versions (or with some option packages!). 6.5 or 8' box are options, depends on how deep your garage is! My 6.5 fits with a couple of inches to spare.
Combo city/highway to work is about 18 mpg summer, 15.5 winter. Pulling the RV in May, we got 11 mpg going out, 10.4 coming back. Likely due to not respecting the speed limit on the return. 4-5% Intersate grades were no issue - we passed everything that was using the climbing lanes, with power to spare.
We did have to get a riser package put on the Jayco to boost it up. Sides of the truck are pretty high, and could not raise the Reese R16K hitch enough. Trailer was at an angle - not real close to hitting the sides of the bed, but closer than I or the dealer were comfortable with. Side benefit is now we have completely adjustable wheel alignments on the trailer. Cost about $700 to have the dealer do.
Truck did not need any mods - airbags, etc. Perfect as the factory delivered it.
We got the factory installed Sidewinder, so we don't need a slider. Did it to save substantial weight in the bed. Also saves substantial cost over a Pull-Rite! Downside is you have to be dead on straight to the pinbox to hook up - can be very frustrating if you are even a few degrees off. I would prefer something else, expecially with hidden rails, but between cost and/or weight, this is what made sense. Note that I was being very, very "anal" about total payload and rear end weight, and this setup fit the bill in every manner.
Actual sticker weight as delivered was 7,407 - so before liquids or "stuff".
Would I do it again? In a heartbeat. This seems to be the perfect solution to the need for a commuter vehicle and a tow vehicle. And for 2 of us (plus 2 dogs) the Jayco was just right.
Of course, now that we have taken delivery, we find out the first grandkid is on the way...so probably should have thought about a bunkhouse.....sigh!