I use the ones zdog referenced. Only used at the wall socket, though, as they are pretty massive, wouldn't want them on the control panel. Additionally, this was to have an AU standard socket wired to the house mains (by a licensed sparky!).
Kettles are hardwired (at the kettle ends), to avoid the hassles of ensuring water proofness, socket/plug temperature considerations, and also keeping the size of the enclosures down. Control panel end I used NEMA sockets and plugs. Big, but not as chunky as the AU equivalent, large terminals, twist lock and decent cord grip.
Google them, or have a look in my build thread photos linked in my sig... should be in there somewhere.