IMO the nicest neighborhood close to there (and by nice I mean really nice and by close I mean really close) is called Ridgelea Hills. Finding a house for 550K may not be possible however. Adjoining Ridgelea is a neighborhood called Mantua, also nice. Mantua has an unfair bad rap because a zillion years ago (OK more like 30) there was an oil spill there. Exxon Mobil or whoever was responsible came in and took care of it but the bad rap lingers for no good reason. The houses are a bit older but on larger lots. Keep in mind that this is a very affluent area and a 40 year old home is often renovated from top to bottom, so it's hardly old in the rundown sense of the word. Schools for these neighborhoods .... excellent.
Another neighborhood where you absolutely can get a place in the 400s or so is Cantebury Woods off of Wakefield Chapel Rd. in Fairfax. It is not fancy although some of the brick homes are a bit stately, it's a middle middle class neighborhood built in the late 60s early 70s. Very friendly, near several parks and a recreation center (google Audrey Moore RECenter and Wakefield Park). Again, all three levels of schools excellent.
There are adjoining neighborhoods to Cantebury Woods that are also nice. If you like contemporary homes (I don't) there is one called Truro.
Suggest you go over to
www.trulia.com and put in your zip code where DH will be working. Put in your price range and see what comes up. Usually the house address is there. You can then use
www.mapquest.com to see the distance between house and office.
In terms of safety, most parts of Fairfax are safe to ultra safe. There are a few places inside the beltway to avoid, like anything close to the culmore area in Falls Church. Anything close to Pan Am shopping center is going to be very nice. I think you will be very happy here.