Can you even get a new F150 HD Payload? They ended up not making them in 2015, but maybe they've started now with the 2016s.
I tow an 8000# trailer with a 2011 Ecoboost, but as it wasn't a HD payload, I had to bolster the suspension and switch to LT-E tires. Works fine, but HD Payload is the smart/better way to go.
If mileage isn't important to you, I would try the RAM 2500. It is a bigger truck, but I've heard the ride with the coil rear isn't bad. They have a tight turning radius, so are pretty manoeuvrable. If you have any plans to get a heavier trailer in the future, like a fifth wheel, the RAM has more payload.
