No such thing. There's one down in VA at Bailey's Crossroads,the other two are up in MD on the Red Line. Not a big deal if the OP has a car,a big deal if they don't. They also don't sell Spec or Giant,you're thinking of HTO,which does have a location in Tenleytown near the Metro stop.

For the OP,only CF you'll get is the fork at that price point. For mech discs you'll want Shimano or Avid,for hydros pretty much any that use mineral oil(as apposed to DOT) will be fine. If you're going to be on anything other than smooth roads you should avoid aluminum forks with straight blades,they don't ride well. Suspension forks with a lockout are ok,but really not necessary if you have proper fork/tires unless you have CT issues. Most bikes are pretty much equal parts wise at the same price point. It's usually the frame design and how the bike fits you/feels to you that you should concentrate on. Trek's FX range are nice,as are Kona's Dews,Spec's Sirrus,Jamis' Codas,and C'dale's Quicks and Bad Boys.