2005 plus SUV that can tow 6.5k (Edited title)

That is going to be tough to fill those specs. I was in the same boat. I have a horse trailer that is 3K dry weight but was hauling drafts 18+ hands at the time. I didnt haul both drafts at one time but did haul a mini, his meadowbrook cart strapped to the back of the trailer and the draft + his harness and his drag harrrow (light weight). I ended up buying an older F150. It survived 10K miles of this and was still going strong when I sold it.