Thats almost identical to what i did. Ill have to dig up pix on my puter tomorrow.
Tips: If you have the traffic subscription, use your factory cord and punch the back out (by the bolt area), run the cord through, mout the GPS as you want it, then silocone the back hole shut, pack it FULL, then bolt the box to the mount.
Run the factory plug under the gastank, under the seat back to the accessory port back there. Put a 12V socket on it and plug into that. Its all out of the way, youll never notice it.
Ill also post a pic of how I have the box locked to by left bar tomorrow so someone doesnt steal my GPS. Works like a charm.
Also, take a silica pouch (the do not eat thing) from a pair of shoes, and put that inside the box somewhere out of sight. That will make it so theres no condensation inside with sunlight. The box is well sealed, so if humidity gets in there, it gets in the way...
Cheers!