I grew up in Falls Church and also lived in Arlington. rents not cheap in that area, I'd look into falls church or even more west like herndon. that's a great area with alot to do, lots of young people, history, culture...I think you'll have a blast. check craigslist frequently, you'll find something good.
I am also going to the same area you are. BAH is pretty good thier depending on where you plan on living. I will be working in the Alexandria area and we also checked out FT. Belvior, they have new housing and really good facilities. Just a thought.
I choose Fairfax area and it is very nice. Like every place, RENT for the size of place that BAH is intended to cover for your paygrade is within BAH, easy. I have a bus that picks me up at the gat of my apartment if I wanted to (and keep the Harley home - not even today when it was 25 degrees this AM) and drop my off at a Metro, which would take you into about a block from work. Most of it is free when you get your transit benifits.