I have a Dodge Grand Caravan with stow & go seats and it's great for two planes and two people with gear. If you need seating for four with 2-3 2M planes and gear it probably isn't going to work.
Best single vehicle option to meet your needs is probably a Ford SuperCab F-150 with an 8' bed and a cap or comparable GMC/Chevy.
Cheapest deal would be a small enclosed trailer (4 X 8) for when you need seating for 4 and more than one plane, pulled with a minivan for gas milage and when you need only one plane and seating for 3.