Update my php online invoice software

Hello, I have a php and mysql driven online invoice software. I would like it to be updated fixed with the following below. To view a demo of the software, please go to [login to view URL] and use admin/admin as the user name and password. Please note. BUDGET is $400 MAX. 1) Fix recurring invoices. Every time a recursion happens, a NEW invoice should be generated. To be honest, not quite sure how the recursion works right now. 2) The ability to show all recurring invoices 3) Allow the ability to edit the Site Url to include an S for secure server 4) Rip out the current serial code verification and add PHP Audit code. 5) Give the ability to attach the invoice as a PDF file. They can chose from one or the other or both. 6) The ability to make multiple payments towards an invoice. 7) The notes section and message section currently cut off at a certain point. The ability to add more verbiage. 8) Add a PayPal module for online payments. 9) Get rid of the freeze action. Invoices will then not have to be frozen to be paid. 10) Make the recurrence section more robust. 11) Fix the yearly invoice chart. 12) Fix the code to allow it to be encoded by ion cube. 13) Add private sections to the data entry customization for the invoices and estimates. Meaning, fields will be added to the form to create estimates and invoices, but these fields WILL NOT be visible to the customer, only to the users of the system.