I agree with all of Top's comments in post #6.
I like your taste in Airstreams and BMW's. I have a 2002 BMW330ci 5sp with 220k on it; it is the best car I have ever owned. If I ever get a 3rd Airstream it will be a 66-68 Caravel
I tow with a 2008 Tundra 5.7L. It is a great TV, but like all the other 1/2 ton TV, it is HUGE. For the TW I would consider a Jeep or Durango with the 6 cyl and 8 speed tranny or maybe other late model SUV or small trucks with a 6 cyl. They would be better than any full size truck when driving solo. If smallish, bounce it off Andy at CanAm. How about a car?