Hi Steve,
I opted for your contribution after all and it works fine. I've got the default country as UK and Outside US and Canada showing in the State box by entering it on thedatabase as a UK zone id, and everything is passed ok to 2checkout, all the customer needs to do is enter credit card details.
I'm going to delete all other countries from the database leaving only UK with one state namely Outside US and Canada.
Can these fields be hidden easily on the create account page with your contribution installed?
Andrew