The most important thing about getting a new bike is to find one that fits. After that, the other stuff is just add ons. Tires will also be the least of your concerns as far as quality parts go. With commuting, you'll be running through a pair a season.
Disc brakes are nice if you'll be riding on gravel or dirt in the rain, or you plan on commuting in snow, slush, or ice. Otherwise, they're heavy, a pain to keep working well, and just complicate accessory install no matter how much they're out of the way. I'm with Alpha in just getting something with V-brakes and get some all weather pads.