I wouldn't trust that the version of OsCommerce installable via your host's control panel (or whatever) is current.
Typically, things like osCommerce and phpMyAdmin are several versions out of date.
If you can ... get the latest stable version from oscommerce.com and either install it yourself or hire someone (like me - topical spam!) to install it for you.
osCommerce is definitely a powerful shopping cart, catalog, billing, shipping script. And it can be very overwhelming upon first glance. However, once you get things set up it is a great product (open source or commercially licenced).
And as Mitch mentioned it does have *many* billing options either built in or easily added as plug-ins including
NetBilling.
Last I checked there were around 2,400 plug-ins available for osCommerce for a wide variety of features.