PDF Automation - replace body of PDF with another PDF design

I have a pdf document with hundreds of pages and thousands of links. The links are to remain in the same place but the body of the pdf is to be changed with different designs. I'm looking for an automated solution to replace the body of the pdf with a different design and retain all the links. Is this possible? I have several different designs and colors but I do not want to create each pdf separately as this will take a long time.

- The PDF document will have the same fundamental page layout however the inside body needs to be able to be updated, across 100’s of pages.
- The underlying document would also contain hyperlinks which need to be kept in tact
- Quality of the body layout needs to be the same as the underlying PDF
- Solution needs to be as quick as possible as there potentially **100’s** of iterations of the same PDF document.