Ok ... This is a bit too random. But here it goes
Do you have a way of filtering users (and mailing/Pm'ing) based on combinations of either no.of posts, active, join date & filter the ones you are not keen on being given moderation choice. To those members, you can mail them/inform them of the decision & provide them with the details like which forums are available for moderation and to respond if they are interested. Those people you can put up for nomination.
I am saying all this, because randomly putting names I feel will not help, as a) It will go with a flow of conversational choice for names e.g. A referring B, C referring D, C arguing for D etc ... b)People who are being voted for may not be interested in the first place.