BIG Question....Is it your daily driver?
If yes, I hate to say it but if you are buying new then go with the ecoboost. If kills me to say that but if you are just keeping the ecoboost until the warranty runs out then that is a smart choice. From my research you will be forking over big money after the warranty has expired for repairs. This coming from multiple ford tech's not me.
If no, then get somthing older that can handle all your towing needs and haul 4 kids. If you ever want to upgrade your camper to a bigger one you can as well. 2000-2006 chevy suburban 2500 with the 8.1 is what I ended up with for well under 10 grand. I tow about a 9k TT with it and its great. Its a purpose built truck. I have had the 5.3 and the 6.2 and the 8.1 is so much better for TOWING. Only downside is MPG. The Excursions would be a good choice too you just have to know which ones are the good ones.
JMO