Hello,
let me start with my brief introduction, i have been working on odoo since version 4.2, it's been several years now. i have worked on each and every release from version 4.2 to v11, and now slowly starting few projects on V12.
i have worked on a variety of projects involving customization implementation of different modules such as CRM, Sale, Purchase, Inventory, MRP, Project, HR etc.
Related to this project
i have had customized invoice templates before, i checked attached template, i can create similar in odoo,
Regards.