Customize open source software to fit our needs

We would like to use Webzash (open source accounting software) for our accounting purposes but we need some things customized. Basically, we need there to be two seperate login accounts, a user and a manager. The user should be able to do the normal accounting functions, but everything the user does needs to go into pending and must be approved by the manager before the information goes into the reports. Also, users and managers should have a forgot password link that emails them a link where they can reset their password, and a combination of letters and numbers should be required. The software we are using is open source, it can be downloaded at: [login to view URL]