As to where to stay, any of the following areas, but as was stated, each area has its pluses and minues:

Downtown DC (either Dupont Circle or Georgetown - Plus is being downtown is more accessible to all hobbyists, and if you are near a Metro "subway" station, that helps as well.   Minus is more expensive, but deals can be found.)

Viginia (Tysons Corner is best option with a possibility being Crystal City area.  Tysons has some nice hotels and are much cheaper than downtown, but little else around and guys from Maryland and DC dont like to travel their due to traffic.  Crystal City is much closer to DC and metro accessible, but closer in price to downtown.)

Maryland (BWI area has lots of hotels, lowest price of any, but nothing around area and much further from DC area.  This area pretty much eliminates all of northern virginia, some DC - but adds Baltimore hobbyists.)

Hope this helps, and hope you plan a visit.  Please make sure to announce your visit here...