Tow vehicle for a 2015 25' Flying Cloud

I am getting ready to pick up a new 25' Flying Cloud. We have a 19' Bambi now, that I am pulling with a 2007 Tundra 4.7L without a towing package (6000 lbs tow rating). I don't think that this is going to be enough to tow the new trailer. I probably carry up to 500 lbs in the truck bed plus two people. Any suggestions for a new tow vehicle. 1/2 or 3/4 ton? Gas or Diesel? Needs to be a truck for my other stuff. Thanks for any suggestions.