Help! Startup needing backoffice support?

I am looking for any recommendations regarding backoffice software or ASP (Application Service Provider) companies to help us with authentication, subscriptions, invoicing, billing, and/or customer support.

We have a short list of companies to provide some of these services, but since we are setting up a WISP to service a few thousand people, I wanted to see if the board had any advice. We will be installing the WISP towers and also hot spots in the next 5-6 weeks, so please let me know your thoughts.

Any and all comments/suggestions/gratuitous sales pitches are welcome. Thanks again.

You might want to take a look here: http://canopywireless.com/services_affiliate.php