Good points, all . . . I too live outside the mainland US (US Virgin Islands), and can't find a lot of things locally.
For me, it's a foregone conclusion that the Internet (and in particular, Ebay) are the answer to lack of local availability.
Even if only for that reason, I'd have some kind of credit card, even if it's prepaid, or a debit VISA or MC.
Another option that works many places is to sign up with PayPal for Ebay purchases, in which they debit your checking account directly. Not sure if there are geographic limitations on PayPal, but may be worth checking out.