Dynamic Configuration of IdP

[M]

I am new to Shibboleth and to SAML in general.  My project team is currently working on a project with these requirements:

1. A large web application provides a service for a large number of customer organizations.  We are now adding SSO capabilities.
2. Each customer organization uses one IdP, but different organizations use different IdPs
3. One instance of Shibboleth will service all customers
4. The support organization will fill out an online form to configure the IdP settings for each customer organization.  The settings will be saved to be used by Shibboleth to allow for single sign on.
5. Each organization has its own login URL, so the system will know which IdP to use.  

Our main question relates to #4.  From our research, it looks like one way to save the IdP settings is to create a new shibboleth2.xml file each time an IdP is added or updated, but is this the best way?  Our web application is in java, and has a database so are there better ways to save the settings?