I recommend that you keep the cigarette lighter plug and buy the adapter. Various power supplies come with a cigarette lighter output. Eg. this one that is currently at a bargain price of $79 from Dick Smith Electronics - I bought one (then tweaked the adjustment to bring the output voltage down to close to 12V rather than the 13.8V - well because I could and it seemed like a good idea).
http://www.dse.com.au/cgi-bin/dse.st...uct/View/Q1755
And the Jaycar version of crocodile clips to a cig lighter socket is Cat # PP2007 ($7.30)