Letter of Support needs hundreds of signatures

I have a letter of support that I want to put out to my community. I am expecting to get hundreds of signatures. I would like to include signatures and a text box so that people can also fill in their name, title, and organization. I have tried to figure this out with bulk mail and e-signatures but nothing seems to work. What is the best way of sending out one document to hundreds of people and getting hundreds of signatures back on the one document?