You need a full size pickup.
I have used an import SUV and they just don't cut it. The springs are just not cut out for any heavy loads. More than a couple hundred pounds of tongue weight and your lights will be shinning at the moon. The domestic SUVs are not much better unless you get an older one or one with a V8.
I now use a one ton single rear wheel dodge crew cab. This is my primary ride that I drive to work every day. I can get ~20 mpg on the highway due to the turbo diesel and legally pull 14.5K lb trailers.
To date the heaviest I have pulled was ~10K lbs. It would be possible to get a speeding ticket pulling this trailer up a steep hill.
You could forget you even had a 6k lb trailer behind this rig, and still park in a garage due to the short box.
Maybe over kill for you but a used 1/2 ton or even better 3/4 ton domestic truck would fill the bill nicely.
Diesel will cost you more but run about twice as long.
The only import that I have seen that could fill the bill is the nissan titan, but that means a new truck and probably $23K minimum.
Fred