[akhtene]

I don't agree that Aragorn could be a good choice as a next Ringbearer. By no means I want to underestimate his qualities and right. But there were other things at the time no-one but he could accomplish.
And besides I think Aragorn was too great a figure to be overlooked by Sauron (as it happened in case of Frodo)

I think the best candidate would be Sam, determined to carry on his master's burdain, too humble to claim the Ring for his own and anonymous enough not to be noticed.