You'll need to get an adaptor if you want to plug the mic directly into the cam. It has a 1/8" mini-jack, but it sounds terrible and the design is weak. You can use any XLR mic with an 1/8" adaptor, so any mic will fit it, but I wouldn't recommend it due to the poor sound quality of the input type.
It would help to know what your budget is. I have used the Canon MA-200 adaptor for the GL-2 which is running for around $170 so I could digitally connect an XLR cable through the advanced hot-shoe mount on the cam and it sounds very good. If you can get a boom operator (and you'll need one if you're shooting outside in Manhattan), he can just rrun a line into that and monitor the recordings using the headphone out on the GL-2. Depending kon your budget, I would suggest the Sennheiser ME66/K6 mic which is fairly directional and has a very nice sound. It runs at around $500.