Mylan,
You might want to also consider where you will be living and riding in Philadelphia. Bike theft and vandalism can be a problem in some areas so a new $1000 bike make not be the best option to be parking outside.

One idea you could think about would be picking up something off craiglist when you get here and have a local shop install a dynohub or swap in a dynohub wheel. $150-200 should get you a very usable city bike and then add your hub and lighting. Might even luck out and score one already setup with a dyno. I just saw a local junk guy selling an english 3 speed with front dyno and front rear lighting and fenders. It needed some work but it was only $40. Another $150-200 and that bike would be great.

Start checking craiglist before you come then you'll have an idea on what's a good deal or not in the area. I can recommend some shops also if needed.