Join Date: May 2006
Location: Washington, DC
Bikes: 2008 Pedal Force ZX3, 2006 Jamis Eclipse, 1997 Marin Indian Fire Trail
The traffic and tolls can be an issue, but that's part of living near a major metro area with a high commuter rate.
As far as places to live, if you are open to living in a smaller town, look into Marshall or The Plains. Both are on the I-66 corridor, and both are gateways to incredible cycling on quiet roads, and aren't too difficult for a commute to Reston (mostly on back roads).
Leesburg is also nice, given the proximity to the W&OD. Chantilly is not too bad for commuting to Reston, and also has good access to cycling excellence. However, the create cycling territory only truly appears past the Loudoun County "sprawl line" (an area that rapidly changes from dense subdivisions and retail to farms and older houses). Other good places to consider (that have good access to cycling) are Herndon, Great Falls, Potomac Falls, and Ashburn.