John if you're looking for the gx16 type connector, I use a site called dealextreme in china for all sorts. Heres a link for all gx16 connectors they do from 2 to 9 pins.

gx16 - Free Shipping - DealExtreme

Go into the connector you're after and they have bulk discount options. I worked out for 50 gx16 4 pins, plug and socket at around £37 with free delivery.