Before we get a wiki or something up, we can collate documentation for scanning and things here.
I got a second 'scan' entry in the printer's address book. It is the one which scans to \\x.x.x.155\scan which you want. What I couldn't figure out is how to delete entries from the address book, so there is the old 'scan' entry plus 2 entries for 'oak'.
I had to chmod 777 the 'scan' directory. If samba is running under a special group, then we could chgrp the directory to that group and reduce the permissions to 775. I didn't check to see what permissions the files are created with. You want to be able to delete/move them.
Do we want it to scan to PDF or JPEG? If you can choose with each scan, then it doesn't matter so much. But for what I do with stuff I scan - images for editing, rather than PDFs for printing, I'd think that JPEG would be a better default. It is PDF at the moment I think.