Taking the "Street" (part no 01-052-0310-0) option of Touratech Zega panniers looks like a good option as hopefully on times when I am away for a short time I can (hopefully) still use the OEM System panniers... A guy called "Des" on the site has a set that look very nice and fit for my purpose.
Also, if I trade the GS I can (hopefully) bang the bike out with the System panniers. Although at the moment I have no intentions of flogging it off! My bank and I have an agreement that I keep it for another few years!
I've emailed Touratech GB and DE to see what the options are... I've seen them on the TT website and just need to check what other messing about there is to do as well as fitting the shorter rear indicators.