Carl & Ona -- Welcome to the Forums! You have gotten this far without us but we'd sure welcome your input and experience helping other folks. I don't have any rivets so take this with a grain of salt ...
. Here is the breakdown on earning the rivets that appear below our user names. This is just a fun way to see who has the most posting action.
New Member (0 posts)
1 Rivet Member (5 posts)
2 Rivet Member (20 posts)
3 Rivet Member (100 posts)
4 Rivet Member (250 posts)
Rivet Master (500 posts)
Longer Airstreams have fore-and-aft beds and more bathroom/wardrobe space. That's pretty nice by itself. Longer Airstreams do limit your ability to find state park and national forest campsites that are long enough. 25' is a frequently mentioned compromise -- you'll experience occasional difficulties finding room at some public campgrounds. There is not so much of a length issue with private campgrounds. Reservations are most useful with either public or private!
Your Power Stroke will tow anything on the planet. Being new vintage my Safari is 1000# heavier than trailers of 25-30 years ago. I own diesel for long range performance on all grades with my 25' Safari.
My experience on the Forums is that other folks' busy lives will not allow them to keep an eye out for your preferred Airstream. You still might get lucky ...
I'd suggest monitoring the classifieds on these Forums
and at Vintage Airstream Club
. Patience will pay off. And again, Welcome -- and let us know how your adventures fare!