GMU is a great school and places half-way well at biglaw firms in DC (at least for law review/top of the class students). I don't think GMU has fantastic name recognition outside of the DC/VA area in general (it is fairly well recognized in legal academia though). Safe bet that essentially everyone in the legal field in DC knows about GMU. GMU recently sent its first student to clerk on the Supreme Court which I think also gave the school a moderate boost in recognition. I don't know anything about UB.
You could perhaps defer your admission for a year, move to NoVA now. Work for a year doing something interesting (probably in DC) and start after you've gained residency here.
You should also consider the differences in culture and style from one school to another. GMU has a strong law and econ faculty that is probably bested only by those at HLS and Chicago (Stanford also has one truly exceptional L&E guy). If you absolutely hate L&E GMU probably isn't for you though as I think its even a required course now (as it should be
NoVA/DC is a fairly expensive place to live. GMU's law campus is nicely located though and its a ~15 min metro ride to DC on the orange line. Figure a minimum of about $1500 for a small apartment in the area (guessing - I live about 5-6 miles from GMU in a SFH). There isn't a ton of parking at GMU and traffic around here is a mess so probably best to plan on living within walking distance of the school.