If you are open to SUV style I would keep an eye out for a Ford Excursion V10 or the Chevy / GMC Suburban 2500 with either 6.0 or 8.1. I pull a trailer that weighs in roughly 8,000lbs and with the Excursion I have had two dogs, four adults and a kiddo in the vehicle.
I can tell you the depending on where your at the market dictates the cost for the 2500 Suburban / Excursions as they stopped making them.
And the statement above about 8,000lb tow capacity is incorrect. The Excursions were produced until MY 2005 and then were discontinued. They are based on a 3/4-ton platform and come with three engine choices. The 2v 5.4, 2v 6.8 V10 and 6.0 PSD.
And fuel comments on the V10, mine gets the same mileage as my previous 2008 Chevy 2500HD with the 6.0. Actually gets better towing.