RMA System alterations

We have already had a RMA System designed and we now require some modifications to it, mysupportsite DOT co DOT uk. It runs on MYSQL Database and PHP. We are providing support for other companies now, not just our own products. Our new clients customers will be required to go to a new link, such as ?TestClient or /TestClient The system should log the TestClient in a field with the RMA, which is displayed on the main admin side and the customers RMA Ticket. The TestClient field should be added to the RMA form so we know which client they are for without having to log on to the system. The Client should be able to login into their admin side which will just show their customers returns, not all of the ones on the system e.g /TestClient/Admin We would like to be able to Filter returns on the main system by Client. We need add admin section to add new Clients We also have a few extra small parts we would like completed. Let us know if you are experienced and wish to do the project, no ridiculous offers please. Thanks