Did you follow "Additional Requirements" section under https://helpx.adobe.com/in/experience-manager/6-4/forms/using/installing-configuring-aem-forms-osgi.html

One needs to go through and understand the complete PDF/A1b spec in order to understand the changes done to the regular PDF documents to convert them into PDF/A files.

Praveen, Please suppply complete stack trace as it is not clear form the exception trace as to which node is giving oakConstraint exception during the installation of AEM Sp1 package.

Plase share the exception trace that you see in the error log file. Also provide details regarding whether the AF is XML schema based or XDP based? If not is not based on XDP then did you specify some Document of record configuration for the same? If yes, please share the details around it.

AEM Forms supports zip file upload which can contain hierarchy of folders and files (PDFs, XDPs, Images etc). So you can simply create a zip of all PDF files on the disk and upload the zip file.