Thanks for all of the help guys.....and yes Jim, I now fully understand about these BCR's and the PS3 system.
Melgar......I've checked all six of the RailKing loco's and 5 will need BCR's.
My next biggest issue is actually getting them here in Australia. I have made preliminary E-mail enquiries with a company in the US called "ModelTrainStuff" who appear to be able to send them to me through the post. Who would have thought...sending batteries on an airplane and through the post, but in reflection, they are not really a battery as such, but more of an electrical capacitor, so it should be safe.
Anyway, thanks to all of you O Gauge Forum members who have come to my emotional rescue once again.
Peter (Buco tragic) on the fabulous Gold Coast in sunny Queensland, Australia