CiviCRM Invoice Template on Drupal

Based on a Word Document we need to have PDFs created from CiviCRM for all confirmed Event bookings. This PDF needs to be send along to the participant as an invoice in the last mail he receives once he confirmed the participation in the event. The invoice will include the address of the participant, the event name, the price options the participant has been choosing, the VAT (this is custom code, not stock CiviCRM) and the invoice number. This invoice should be attached to the event participation record and if this is not possible, attached to the participant (you can upload files to participants). In addition to this being sent out upon Event confirmation, we need to create a functionality to create all missing PDFs (so for all already existing confirmations) and attach them as described above. Last but not least we should be able to download all created invoices in one go (e.g. one zipped file with all PDFs included or even better, one joined pdf). Use a date range filter for that (so we can download all invoices for a given date range). Oh, and this needs to work in CiviCRM 4.1, Drupal 7, in case you wonder.