This unit was mentioned somewhere recently - lots of connections, can be paralleled up for more current...
http://www.ebay.co.uk/itm/22mm-12-2A-12-Wires-2-amps-12-Conductors-Capsule-Compact-Slip-Ring-220VAC-250Rpm-/300705656201?pt=UK_BOI_Electrical_Components_Supplies_ET&hash=item4603742d89
there are a lot of entries for "slip ring" on eBay.