If you can use stripe, that should be your first choice. Failing that, 2Checkout and http://www.fastspring.com/ http://www.fastspring.com/ are really good and

If you can use stripe, that should be your first choice. Failing that, 2Checkout and http://www.fastspring.com/ http://www.fastspring.com/ are really good and 2Checkout works in many countries. The other option would be to just get your own merchant account and use something like WorldPay