OK, here's a very quick first draft of the motion and election rules for STV.

http://uk.wikimedia.org/wiki/User:LondonStatto/Proposed_EGM_Motion_on_Voting_System 

http://uk.wikimedia.org/wiki/User:LondonStatto/Proposed_STV_Election_Rules 

Thoughts, questions, suggestions all gratefully received. I'm not at work tomorrow so will do my best to monitor email/talk pages.