I've spoken to the Electoral Reform Services person who's managing the election. The voting will be full STV for the 4 posts, therefore it's worth putting up conning four people to stand.
If you want to find out more about STV and how it works, take a look at http://www.electoral-reform.org.uk/?PageID=483
The important thing to note is that although you have only one vote, if your preferred candidate is either elected or eliminated your vote is transferred to your next preferred unelected/uneliminated candidate (until the four have been elected). Thus it's important not only to have four candidates but also for us to express our preferences in the same order together.
I've run many elections under STV for a student union (15,000 voters, 30% turnout for the senior posts); the reallocation process is hellish on paper, but now we have computers it's a doddle....
Cheers,
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Dave Parry