I would like to switch from my 1984 wedgeback car hauler to a Dually with a multi car trailler to haul my Jeeps. I will end up with a 3car humpback trailer, but may have to start with a 2 car bumper pull trailer. I am getting to that age where I am tiring of not having the amenities of a newer truck.I am looking to spend no more $12,000 for a dually. And I have made my mind up I want a diesel. It doesn't have to be the newest thing out there, I just need a solid reliable truck that can pull around 20,000lbs. (5k for each Jeep and 5k for the trailer) I would like A/C, *** Man trans, 6sp maybe?,(auto is not a deal breaker) and for the truck to be very reliable. I have even seen F-450/550 work trucks in this price range. I thought about getting a flatbed F-450 and putting one Jeep on the bed and towing the other two on a trailer.From what I have found, I should probably be looking around the year of 2000. So my question is, which truck would best suit my needs? And do I even need a dually, I have seen some people towing this setup with single rear wheels?