A rating per person would make it easier like on BTCJam where people are willing to loan out bitcoins to people who could disappear.
I think instead of finding people who are willing to hold the risk of a default, you should come up with a mechanism to
make credit card payments irreversible.
Good luck with that.
Exactly.
The credit card companies are duty-bound by the law to enable chargebacks, so even if THEY wanted to offer a no-chargeback payment system they couldn't.
Something I have seen around the Web are these so-called "chargeback waiver" clauses in merchant TOS but I'm not sure how legally binding they are, if there were they'd probably be commonplace by now.
So barring any fundamental paradigm shifts in consumer protection laws the better course of action would be figuring out a way to make (international) bank transfers as cheap and painless and possible, something I could do from my computer in a matter of seconds.