If you have access to use a Credit Card with a billing address in any of the supported countries you can sign up for a Subscription and you can use your FormsCentral account from anywhere.
I don't believe there are restrictions on where your Paypal account is for the Paypal integration to accept payments through your forms. This tutorial on setting up Paypal talks more about the requirements: http://forums.adobe.com/docs/DOC-1632
This FAQ lists the Countries supported for purchase:
This FAQ on the "Unsupported Country error" gives some work arounds for how to get a subscription set up in your case: