I have found one that does everything except for associating it to an item on the invoice. It does associate it with an invoice though. It also allows a customer or admin to add/delete an uploaded file that is associated with an invoice. I asked them how much to add in the option of it associating the upload with the item instead of just the invoice and they came back saying it would be $295 to do the customization to add this feature. Not a bad price and maybe after someone pays that for the first time, they will add it to their product for future versions.
http://www.commercexp.com/products/crel ... rsion.htmlFeatures of the File Attachment Support module:
Allow user add multiple file attachments to the order on check out, or view/edit order page, user can also remove or download existing attachments
Allow admin set allowed file type, number of upload files and maximum file size for upload
Shows attachment file size, date, and uploader ("by admin" or "by customer")
Allow admin add file attachments to the order(s), admin can also remove or download existing attachments
Allow admin to turn on off the file upload feature
Ajax based uploading, fast and easy to use
Easy installation, seamless integration with CRE Loaded 6.2-6.4