TMax 3200 is a fantastic film. I love it because it looks to my eyes a lot like the previous version of Tri-X, but it's sharper and somewhat finer grained. My advice is to shoot it at 1600, and just go have fun with it. It's great for evening and night photography. With a hand held camera and 35mm f/1.4 lens I've been able to get nice 16x20 prints from 1/15th second shutter speeds. That seems to jive with what most street lights provide good light at. You could even shoot at 3200 at 1/30th second and not worry too much about camera shake.
I used Rodinal, FX-37, or replenished Xtol to process. All worked really well. The film loves any developer you throw at it. Just run one or two test rolls to make sure you have your process down before you embark on your adventure.
Enjoy the film!