I agree with your wife. We went from a 30 ft 5th wheel to a truck camper! I DID NOT LIKE IT! Too cramped. I see there are larger ones with slides but I don't know if they are too heavy for a Ford 250. Still would be cramped.
Anyway, we went to a 29 ft Class C Winnebago Minnie 29B. We often travel with our two grands, close to your children's ages. Sometimes I wish we had the cab-over single and/or double bed. Sometimes both kids sleep head to toe on the jackknife sofa, or one sleeps on the dinette bed. It is a pain having them in the living area, but we usually go outside for our morning coffee, anyway. (or if traveling, just start driving as they continue sleeping.)
The jackknife sofa bed is large enough for an adult and a child. The dinette could fit two kids or one adult.
We did buy a Honda CRV to tow. We have only towed the car twice. Other times, when on a travel trip we move most days so the car isn't necessary. When we stayed at a local campground for two weeks we drove our pickup separately to bring the bikes and such.
I would be tight in a less than 25 foot rig. Many smaller rigs don't have windows on both sides. I like to look out both sides to see the sights while traveling.
Enough of my ramblings. For you I would consider a gas C or A about 28-30 foot with side windows on left and right for site-seeing for passengers.
Mike Leslie
2003 Winnebago Minnie 29B