FPP doesn't really work for selecting N candidates out of M. The software is very simple to use, and is available at http://stv.sourceforge.net/.
I'll look at that but can you elude as to why it doesn't work? With FPP you pick the N top ranked candidates and they become your committee members.
I can't seem to come up with a concise argument in my head, although I *know* the reasoning. The wikipedia artcle on it links to several good articles though, discussing the relative benefits (and problems) with STV. It basically boils down to reassigning unused votes. If I could vote for three people out of eight, it's very possible that none of my three votes would be awarded to people that end up winning. If the distribution of votes is relatively flat, this could result in a large number of votes being wasted. STV assigns preferences to candidates, so in the event of your primary choice being eliminated (or, I think, voted in with a large majority), your vote is effectively redistributed to the next candidate on the list. You end up with being able to pick out things like "no one could agree on a first choice candidate (equal spread), but everyone[1] agreed that Alice would be second best". In this case, Alice would probably get in. Under FPP, even though she was a strong second choice candidate, it would merely be the frontrunners that got through. [1] Everyone that didn't put Alice as a first choice candidate, of course. I'm probably not explaining it very well - if I'm outright wrong, I hope someone will step and correct me.