I have popped the phrases “Montana” and “fifth wheel” into the ebay search engine several times and have always been amazed to see it find something. There is seemingly NO end to what is listed there!
Let us know how this goes for you.
You do not mention if your truck has a short or long bed. If it is the former, I would suggest the PullRite SuperGlide. It is the most pricey hitch on the market, but it is also the best for people with short bed trucks. You NEVER have to worry about the front of your 5er “kissing” the cab of your truck as the hitch slides automatically to provide clearance space. For me, it was money extremely well spent.