I'd go for using AD as the primary directory source as well. That will cut out the need to create users in OD with separate usernames and passwords etc.
If you join the Mac server to AD, you can then set up shared folders per user and mount at login. We've used a script in the past to create the folders. In this example we have a csv file (called "names") that have the list of AD user names that we want to create the folders for:
#!/bin/bash
list=`cat /path/to/names`
for name in $list; do
mkdir /Path/To/Shares/$name > /dev/null 2>&1
chown -R $name:admin /Path/To/Shares/$name
chmod -R 700 /Path/To/Shares/$name
chmod -R +a "$name allow delete,readattr,writeattr,readextattr,writeextattr,readsecurity,writesecurity,chown,list,search,add_file,add_subdirectory,delete_child,read,write,append,execute" /Path/To/Shares/$name
sharing -a /Path/To/Shares/$name
done
exit 0
You can mount the share at login via Casper with:
#!/bin/bash
# Mount the drive
mount_script=`/usr/bin/osascript > /dev/null << EOT
tell application "Finder"
activate
mount volume "afp://servername/$3"
end tell
EOT`
exit 0
