There are plenty of high level options out there but personally I'd be aware that if your bike is tail chopped they can look a little 'wheel barrow' like and depending upon our view can also make the standard footrests look odd as opposed to a nice pair or rear sets.
(I'd wager this is actually for a 600 rather than a 620 as they list it for a 750 and 900)
http://www.ebay.co.uk/itm/Official-D...QAAOSwys5WVeZ1
These Mivv ones look good with the original footrests and still use the mounting point making them look a lot more like they are supposed to be on the bike, if that makes sense?
http://www.ebay.co.uk/itm/Exhaust-MI...8AAOSw9r1WDTp4