The only thing that will determine what currencies you can accept (bill in) is your merchant account.
Granted, Infusionsoft can only DISPLAY currencies in a few formats on the back end, however they do have integrations with merchant gateways that support billing in other foreign currencies (see list here:
http://help.infusionsoft.com/default.asp?id=1801&SID=&Lang=1).So for all intensive purposes, you could bill in a foreign currency even though the currency symbol may not match in Infusionsoft---and as long as you know this you should be fine.
The real problem though is with customers. They WON'T be okay with currency displaying in a different format that what they paid in---thus the other currency symbols are supported via CustomerHub.
As a matter of clarification, in the case of both Infusionsoft and CustomerHub, 'supporting' different currencies simply refers to displaying the correct symbols, not anything relating billing (which is all done at the merchant gateway level).
We offer a free 30-day trial of CustomerHub, after which the service is $39/month.
Best,
Kyle