I would suggest you start browsing some online sites to get a sense of housing prices around the Vienna metro. It's the closest Metro stop to Mason and the closest to Herndon, and the Fairfax/Vienna school districts. See if you think you'll be happy with what your money can buy/rent in that area. I don't know what kind of living environment you're looking for; you might also check out East Falls Church and Ballston. Ballston is very walkable, with lots of stores and restaurants and high rise apartment buildings. Not much is walkable from the Vienna station.

If the housing options right around Metro are too pricey for what you get, then start expanding your search to the major bus lines in Fairfax County.