Send one randomly selected user's name & picture to another

Hi,

I have a client who needs a site that will randomly select a user[1] (of a specific role e.g. ‘subscriber’) and send (via email or notification) the name and picture of that user[1] to another randomly selected user[2].

This is for a large group of people playing the game ‘assassin’ (basically using soft dart guns and the like to assassinate each other).

The users cannot be selected twice – i.e. only one person sent to each user, but user[1] can have user[2] and vice versa.

The plugin must be able to be used more than once and not give the same results. All users must always get another user’s details.

I cannot find any plugins to help me and I am really bad at PHP, I have never made a plugin, I’m more of a theme designer.

I was thinking something like: array_rand() but i’m not sure how to use this with WP roles.

Thanks,

Eric.