Yes. I could help you integrate one of those databases or api's if your client decides they need that.
Different countries generally use different domains.
This is another way many people do this. If you go to http://www.yourdomain.com you may get $ but if you go to http://www.yourdomain.co.uk you could get £ and you could secure domains for other supported countries you want as well.
Then you can get the correct currency based on the domain itself just like a session variable.