Stacy,
Guess I am a bit puzzled. There is FGAJVCD in Banner 9 INB (admin pages). That is journal voucher entry. We use that form here.
Is your institution not using Banner Finance approvals process at all? If not, then might want to bite the bullet and pay for consulting assistance to configure that. FOASYSC form, which you may not have access to, has an APPROVAL OVERRIDE INFORMATION page on it. That is where you can turn approvals on/off for 8 specific document types, including journal vouchers. Can set for if turn on if impliciit or explicit approvals. The basic process is, if approvals turned on, when complete a document, that sends to the approval process. FORAPPL will process and based on approvals configuration, assign the approvals needed, with the concept of approving in order (though the option to approve out of order). FORAPPL keeps running and checking for the last approval. If NSF, after last approval, will send to NSF queueu for that approval. After last approval, then sends to the posting queue (FOIAPPD). Posting process will run and post.
Storing documentation. BDM (Banner Document Management) is what Ellucian will recommend. Can access from Banner INB (that is the RETRIEVE option on top right of a form page). That is a whole other topic. If not using BDM today, probably will want to pay for implementation assistance.
Journal voucher entry is pretty basic in my mind (FGAJVCD). The approvals is the complex part. That is where would need consulting help if no one there knows how to do Finance approval configuration. That would be a multi day class to learn that.
There is an option as well to use FUPLOAD to load a journal entry into GURFEED and feed to Finance, but that is clunky (1990's type technology).
Very high level response. Hope this helps a little.