ISPWizard can be with any billing package which supports signups using the Microsoft IEAK (Internet Explorer Administration Kit.)
The following ISP Billing Packages claim to support IEAK signups and so should be automatically compatible with ISPWizard:
To use ISPWizard with your existing billing package which supports IEAK signups, just enable Online Signups under the Signup tab of ISPWizard, and fill in the required details on the General tab under that. The settings on the other tabs can generally be left on their defaults, but you can adjust them to suit your preferences if you wish to.
When creating your signup username/password
please remember to enforce restrictions on that user to prevent it from
being used to get free access to the Internet. ISPWizard doesn't
provide any method to prevent such misuse of the signup account as any
client side restrictions can be easily bypassed by knowledgable users.
ISPWizard - Internet Setup Program Wizard