It's been like a month and no replies?
I was watching this thread, because I'm curious, too!
Maybe we all don't know the best brands because all they say is "Proline"?
Seriously, though. It would be great to hear some real-life stories of things like bolt-holes not matching up, etc. If you're about ready to plunk down $4000...a guy wants to know things will fit. So far, with my Rover, I'm about 30% in the "doesn't fit" category for nearly everything I've bought. I'd hate to do that with a Galvanized frame, too. Literally take apart 100% of the Rover and find things won't bolt up to the frame I spent months waiting for?! That'd be a nightmare...
At least tell us which brands to AVOID, if you folks don't have a favorite, yet.