Towing my 6700# loaded toy hauler (7760# GVWR, 5025# UVW) with 780# tongue weight put my truck GVW at 180# under the 7100# GVWR, but only 50# under the rear axle 3850# GAWR. The truck has a 1607# payload, very similar to the OP. I have had one short episode of porpoising on the interstate. I bought some Torklift Quick Disconnect Stabiloads and will install them soon. I have moved some weight out of the truck and into the camper since the trip when I weighed it. I will not try to tow anything heavier than this camper. The Ecoboost has no trouble pulling it, but the truck chassis is LOADED.
I advise the OP to get to the scales with what you have now before deciding to upsize the camper. You didn't list any numbers in the post to indicate what your actual scale weights are. It takes three passes across the scales and about $14 to find out what you have.