Until you have more expertise, I would suggest that you get more than one opinion or check carefully on references of any contractor/timber framer that you engage. Most framers that I know of are decent, honest folks but I have heard a few not so happy tales. There is a recent posting in this forum about a new frame with some questionable joint pegging techniques and it happens to be in southern PA. Rehab-ing an old barn can be an expensive endeavor and it would be a shame to see your money spent in-efficiently. If you can afford it, it would be wise to 'do it right'. Just don't let someone sell you a bill-of-goods.
You have another option, as I'm sure you know, and that is to sell the barn as a package or as separate timbers. This saves the material for future use and solves your problem of dealing with a failing structure.
I agree with the idea of being able to say "I OWN a Pennsylvania bank barn". Good Luck!