Richard,
the current version of the payment service contract does not support multiple
currencies. This, however is easily ammended. With respect to which credit card
processor to use -- Authorize.net or Verisign's PayflowPro -- both are very comparable.
In both cases your site will have to communicate with another web server, either via
https or a propriatery protocol on top of tcp/ip. Pick the one you feel most comfortable
with. And don't forget to compare prices and support of both vendors.
For CVS access read the CVS howto at:
https://openacs.org/new-file-storage/download/cvs.html?version_id=140
/Bart
