In case you've not noticed the for-sale secton thread, my luggage system is up for grabs (seat-bag and tail-bag that zip together). It's the BMW soft luggage system specifically designed for the F650GS/ CS, Dakar and is likley to be suitable for the G650GS too.
Linky >>> http://www.ukgser.com/forums/showthread.php?t=297543
Linky >>> http://www.ukgser.com/forums/showthread.php?t=297543