I got lucky and bought a 1600gt with the top case. My last bike was a 1300gt and I bought a case from the dealer for it and they painted it and keyed it for me total price around 1200 in 09. the case you get that is for the 1600 is a better looking case but is a bit of a pain to take off because of the wires and you have to un-screw the seat now to get to the plug. Also the 1300 case hand a handle to carry it when you released it from the bike, new one does not. I think case from a r1200 or 1300gt will fit your bike and you will have to paint it and key it though. if you buy new and do all that it will probably cost about the same as ordering one for the 1600.
The decals are vinyl. They are originally for a car and I cut the whole part into three pieces. It brakes up that terribly bland "Weissaluminium" color a little.
I have no idea who decides upon colors at BMW Motorrad. Definitely one of their weakest points. They always seem to have one really blaaahhh color in the lineup.
For 2012, the prize goes to the K1600GT!
78 BMW R100S, 90 BMW K1; 99 BMW R1100RT, 12 K1600GT