I think my Revo (bought Sept. 06) came with a sailing rudder.
All the kayaks (except the Adventure Island) come with the standard rudder. It is about 11 1/4" long and 46 sq. in. The optional sailing rudder is about 13 1/2 " long and 90 sq. in. Although the standard rudder works pretty well with the Revo, the sailing rudder makes a definite difference! If you're having any controllablity issues (close hauled, heeling for example), the sailing rudder will fix it! IMO, the sailing rudder will also improve your upwind tracking slightly ( it augments your fins, allowing less side slip). You can also get further upwind performance gains with the larger Turbofins.
If yours came with the sailing rudder, your dealer might have included it with your sail.
Max, you would probably want the Sidekick amas rotated up for sailing to minimize drag (notice the aeronautical term?), using your body to counteract the heeling angle as much as possible (you'll be surprised how much you can "hike out" with the Revo when you get used to it). This also keeps the upwind ama well clear of the chop. The leeward ama will take over when the boat starts to heel more. But why not experiment around?