Word/PDF file with check boxes that automatically add and merge PDF's into 1 file

Greetings!

I would like to make a Word/PDF file (i think Word will be the easiest) that is like an index.

This index will contain all the needed technical documents that our clients could ask for.
But not all the clients need al the documents. So i need to chose which one i will send.
Now i have to merge the files that they need and make an index by hand.

I would like to do it with check boxes in the index. So if i click on the check box and the check mark appears, the document that is linked to this box is automatically added and merged to a pdf file.
This way i can click on all of the check boxes I need and all the files will be merged into 1 PDF-file.

The adding and merging have to be in the order of the index.

Then i can send a PDF file with the full index with check marks in the check boxes that my clients need and all the needed documents.

If it's possible i would like the empty check boxes automatically deleted when not clicked on so the index shows only the documents needed for this client.

If this is not possible then it will be fine that the clients can see all the document titles in the index but only the documents with the check mark.

I think this can be made by uploading all the files to 1 pdf and work with making it visible or invisible.

But there are 1000 pages of documents so the PDF-file would be huge and it would not work properly.

Does anyone knows a sollution to do this? Maybe there is an other program that can help?

Cheers

Jens