need advice for truck to pull rv!

So, my husband & I just bought a Navigator that can tow 9,000 lb. & just bought a 32 foot Travel trailer 7600 lb GW. The numbers all worked out; after loaded it weighs approx 8400 lb. However, we need a new Truck, probably a 2500. Not sure a ford or Dodge-gas or disal??? Any suggestions. Our...