Webforms/Landing Pages

I need a way to capture leads and do two specific things:
-Have the referral partner automatically added to the contact (ie referral tracking links)
-Have the ability to upload a document when filling out the form

InfusionSoft has the referral tracking links but no way to attach documents. I also use Jotform, which has a way to attach documents, but I can’t figure out how to get the referral partner automatically added.

HELP!!! Anyone have a solution? Thanks!