I need Supporter to enable buying of ads...

Can any one help me on this? Posted in features but this is actually a request.

I want to set up preset advertising slots on my site (i.e. leaderboard, sky scrapper, etc) then allow supporters to buy based on time slots the ads as they please via the supporter area.
This would need to track what is available and what is not and also pricing for each slot and totalling of multiple slots.
Is this possible?