Thanks gents, that's very useful information. The 1000 pump has the same colour wires so hopefully a pump off a 600 won't get fried. I've been riding around without the pump recently and the bike runs fine until the fuel level is very low, though its range is slightly reduced, so I'm hopeful that solorider is right that the smaller pump will be OK.
Final daft question:- is there a torque reaction when the pump is working?, ie does it need to be secured on both sides, or could it dangle from a single mount without leaping about?