You're almost ready for a nightmare with a 4 cylinder, BTDT. Even a popup camper can be a struggle with a 4 banger. An alternative to using a 4 cylinder is to buy a beater truck for towing. Another is to tow a tear drop trailer but make sure any 4 banger is equipped with the right towing package, i.e. correct rated hitch, tranny cooler, brake controller, and trailer electrical connection.
FWIW, my buddy bought an aluminum body teardrop on the way home from the Fiat dealer. He found out that even the light weight teardrop is a struggle with his new Fiat SUV. It overheats the automatic transmission.