6 miles is a great commute, that is what I have and love it!

If you are going to be riding it regularly, you might consider rechargeable batteries. I got a nice battery charger (LaCrosse BC700) that charges AA's for my headlights and AAA's for my taillights, and the system works well for me. It was an initial investment to buy the charger and batteries, but it is paying off with all of the hours I am logging (versus buying alkalines over and over again) - now that I am a full time bicycle commuter. Just a thought to consider. Enjoy your commutes!