Buying Wordpress Multisite Coding Required

The theme I own: Dreamhome http://furuthemes.com/demo/dreamhome

I would like to have the feature of having all listings on one map: http://themeshift.com/demo/decorum/

Now, here's the kicker. My wordpress is setup is a network (i.e. Wordpress MultiSite) so the properties of all the users on the network should be placed on the map.

Can you do this?

 

I should have put this in the Programming subforum - my apologies.

Al