Pretty much any SUV that's going to have the room to do what you want is not going to get the greatest gas mileage as compared to your Civic. I'm sure I'm stating the obvious. :hihi: Even used 4Runners are quite pricey, but I'd rather pay a little more and get the longevity out of it.
The best thing to do (again, stating the obvious) is to look at the cargo capacity between the Durango that guy has to similar sized vehicles. If they're close, I'd get the 4Runner hands down. I only know one person that owns a newer Durango, so I don't know if it's got problems model-wide, but it is always in the shop for something.