Found these on the 'bay, look pretty good and cheap enough to try.
http://www.ebay.co.uk/itm/271993612304?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
http://www.ebay.co.uk/itm/271993612304?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT