If you get a 550, then all the bits you will need to mount it to the top rail will/should be in the box

(saying that I did buy a cam
http://www.ram-mount-uk.com/rap-319.htm to get a better fit/grip on the rail above the clocks) Put it above the clock as it will be more or less in your line of sight, put it on the handle bar and you will have to keep taking your eyes of the road to stare at the handle bar, rather than just a quick glance down. (imagine you are looking ahead and then look at your brake reservoir then do it again, but look just above your clocks, and then you will see what I mean)
It didn't budge in 30K and off road too


Top tip, is to replace the winged nut that secures the sat nav bracket, to the ram mount supplied, is to replace it with a nylock nut, so some sticky fingered fecker has more of a problem nicking it.
Also put a bit of electrical tape around the bar for extra grip when fitting the above cam!
HTH's
Bike sold, so no piccies sorry!