Advice for project

Hi Everyone,

I am currently trying to work out a way to achieve some functionality in Drupal. I want to allow users to basically "Accept" a node when an email is sent out to numerous users. The "Node" will be a job that is emailed out to specific users on my site - the first user to log in to the site can then "Accept" this job and then the Node will display a message saying "Sorry, this position has been taken" as someone else has already accepted the job.

I was thinking of having this as a new CCK node type called "Job" - so I can fill this in with specific details. But I am unsure how I could also associate this node with one user who "takes control" of the node.

I would also need users to have different categories associated with their profile (which may be a CCK type: Profile). For example,

Name: Mr G Bain

Posiiton: Web/Media

Groups: Web Developer,  Video Editor

And then any jobs that are created can have a checkbox next to numerous "Groups" and once the job is published, an email is sent out to any users who have selected that specific group in their profile. In the example above, Mr G Bain would be emailed if the Job that was created, was aimed at a "Web Developer" or "Video Editor".

I understand the Rules module can send emails out but I haven't seen an option to mass mail out, depending on certain CCK values that the user has checked int heir profile.

Any ideas would be great, cheers.

Garry.