Customize Invoice for WHMCS six with Multibrand installed

I need the standard invoice on WHMCS six to be customized. We use Multibrand, thus the original code has been modified in order to set different logos and features for each brand. These things need to be changed: 1. Omit "PDF has been generated...", omit "Paid, Unpaid" in the upper right corner, deactivate "Transaction part". 2. Either alter the code and add positions on server where we place pdfs for background usage in invoices, i.e /templates/incoices/[login to view URL] or find another solution that enables us to use fullpage-background pdfs for the invoices. It needs to be a pdf with inserted fonts, no jpg or other graphic image that blurs. 3. Change position of "Billingaddress", this needs to be in one line on top of Receiveraddress, we will give you the exact position in millimeter 4. Change position of Receiveraddress, omit "Billed to" we will give you the exact position in millimeter You should have prior experience with WHMCS. Further work may be given if completed successfully, and you have a good working knowledge of WHMCS. Access cannot be granted to the system, as it is in use, so files will need to be sent to us to be uploaded and tested.