May have already been mentioned in here but:
2.7 Eco, most fuel efficient but check the payload - their max payload is usually down by 200-300lb compared to the larger engines. Something that may be especially important with two kids.
3.5 Eco, good engine, more “peppy” than the 5.0, in part because it usually comes with a different gear ratio than the 5.0. Real world fuel consumption is basically identical to the 5.0, even though on paper it’s supposed to be better.
5.0, same fuel consumption as the 3.5 but lacks the 10 speed in the 2016-17 age range, if thats important to you. Currently the 6 speed seems to be a lot more reliable than the 10 speed.
Base trim Lariat is basically an XLT 302A with Sync3, leather seats and most importantly 4x4A, although I’ve heard mixed things about reliability when it’s used regularly.
If you pick up a 3.5/5.0 supercab with 6.5’ box and mid level XLT package (301A for example) you’ll have a payload of around 2000lb, which means you could get a FWC or small/light camper on the back. Alternatively you could pick up a GFC or Vagabond Drifter (when they eventually release the full size - any day according to CS) and have plenty of payload left to kit out the inside with proper camper like amenities.
I have a 2017 5.0 XLT supercab, and chose it for the reasons above - payload over the 2.7. I was preferring the 3.5 but couldn’t find one with the other specs I wanted. Should be fitting a GFC on it in the next month and have most of the interior built ready for it.
Fuel wise, I usually average around 11l/100km (21mpg) with mosy highway and some town driving, and sitting at 110km/h (70mph) in non subzero weather get around 10l/100km (25mpg), goes up to around 11l/100km (21mpg) at 80mph. Although that was with stock wheels and tonneau cover. It’ll obviously go down with AT tires and a camper.
Edit: and ignore the FX4 option. Shocks are so so apparently and you can easily buy better ones for a couple of hundred $. Tires can be changed and most importantly the hill descent option costs $15 aftermarket. It’s a single setting on forscan - the $15 is for the OEM switch you fit into the pre existing wiring.
2015 - 2020 Ford F150 - Adding Hill Descent Control to non-FX4 trucks - ** This post was updated on 5/14/18 For those interested: today I successfully added Hill Descent Control to my 4x4 that normally only comes with the FX4. This mod consists of adding an $8 combination Hill Descent/Traction...
www.f150forum.com
That leaves the skid plates, which can be bought extremely cheaply. Alternatively a set of proper plates from RCI.