Ok to start off...I have about 10 years experience with PHP but just started learning Drupal at the request of management. They are interested in a multi-tenant version of Drupal for a current consumer driven website. I will try to provide as much information as possible.

Version: Drupal 6.19

Technical Information.

1. Current codebase is Java.
2. PHP is new to team so environment will need to be created. Test environment currently exists but not much more than a barebone Drupal install.
3. There are some web services that are available for retrieving existing information but not many.
4. Primary database for existing system is DB2. Not sure if we will be moving some or all data to MYSQL.

Business Information
1. Integrate with health provider directory using existing service.
2. An administration tool to add campaign, products (not a shopping cart but more or less a module to package and manage health plans). This tool will allow for a unique URL for each campaign.
3. Tool to compare plans.
4. Multi-lingual capabilities (this should be an easy one using existing modules but just mentioning it just in case its more complicated than I think).
5. Ability to cross-sell between core and non-core products.

These are the high level requirements. What would you estimate the cost and timeline to accomplish this? What are the steps to port this from a J2EE application to Drupal? Thanks.