best sourcing for community map?

[maciasluis]

n designing a minimal GIS interface for community assets we want to show locations and areas on an existing map. No particular tools or formats or sources have been decided on, but tentitively this will be done with MapServer and be based on the public national road map available from the Census. Road rebuilding and changes are in progress, so it is expected that the basic roads layer will have to be reloaded with the new roads at some point possibly several times during the construction process.

Is clipping these vector maps with some tool a good idea, or would it be better to stick with the whole data set as downloaded and then use an index to quicken map generation? Maybe both? If clipping the raw data should be done, then what method is best for that? Can it be scriped so any new data can be easily clipped the same way?

Thanks for any answers or advice regarding any of these points.