I'm also hitting the road, with my 4 kids and wife, for a year. 6 people. We looked at a 3500 truck and a 3500 van and decided against them. Why? Because when we aren't towing the trailer we will still need to go to museums and grocery stores and malls. Those are some BIG vehicles, but with very little room inside.
My decision was to get a '05 Excursion with the 6.0L diesel, get the engine bullet proofed, and fix it up to my standard. I chose against the older 7.3 because of the weak transmission and the general age (wear and tear) of the vehicles.
Our trailer weighs 7,500 dry. Loaded we will be closer to a realistic 9,000lbs. with all of our gear (read: crap).
While the Excursion is rated to be strong enough, 11,000lbs. of towing capacity and 1,800lbs. of payload (family weighs 750 and tongue will be another 850), we will also be adding to the suspension system for peace of mind. Airlift in the rear, upgraded springs in the front, and let's not forget the best damned brakes money can buy. Stopping is the most important part of towing!
It should be a safe hauler. At least the safest I can find/make. A truck isn't as safe for us, because having a kid sitting next to me and pulling at my arm is a danger, no matter the technology or truck size available. Space to work, to move my arms, is as important as anything else. Keep that in mind.
Also make sure you get the best hitch you can. I did months of research, tried 3 different hitches, and finally settled on the Andersen WD. It's spectacular, consistent, and reliable. Easy to use. There may be better hitches if you're an expert, but my wife can hook us up. And it's always the exact same fine-tuned setup every single time. That's also important; a consistent towing feel and experience.
Ultimately, be safe. Don't be stupid and risky. Remain calm and controlled at all times, and you'll be safer on the road than any piece of technology or spreadsheet can provide to you. If the driver is tired or grumpy, hopped up on coffee or not feeling well... don't drive. There's less margin for error here.
Safe towing!
