I want to start a project to document my local government starting at the municipal level and going upwards from there. I want to build an interface to allow people to look up their representatives and their public servants by issue and geographic area or issue and get their contact information back.
I want it to to have fast lookups so community organizers will come to my site first they want to find out who does what. I would also like it to be able to scale geographically so I can get local activist could have their own copy of the database on a local server that they can also delegate access to. I would like to delegate updates to a development version of the database to other people similar to Open Street Map, but I would still like to verify changes so there won't be a flood of bad data. The presentation and the data storage will be separate components.
Knowing this information could you tell me what data management engine would be more appropriate for the task?