[Laneco]

Okay - I do 24 hour mountain bike races solo and that makes me a gen-u-ine expert at night time riding... If you are only going to have one light - make it a helmet lamp. Try changing a flat tire in the dark with a handle bar mounted light or climbing a set of stairs carrying your bike in the dark etc. Two lights one on the bar and one on the helmet is best. But for one, choose the headlamp light.

Headlamp lights do offer a distinct disadvantage when it is very dusty (unlikely for you) or when it is snowing. The light tends to reflect back from the dust and snow into your eyes. For that example, handlbar lights work best.

The helmet light also lets you make real strong "eye" contact with cars at intersections. Before you make a left hand turn, even if you have the right of way, look DIRECTLY at the driver of the car. Shine your helmet light right into their face, then look away and turn your bike safely. Also, that scary noise off to your side, you can turn your head with the light and SEE what it is...

Many good makers of lights out there. I use a NiteRider system that I've had for 4 years. The newer ones are better, but my old one is fiercely bright, gets 4 hours out of each battery pack (I have two for racing) and after 4 years, lots of training in the dark and five 24 hour races, I'm still on my original bulb. Bombproof.

You do not need a $400-$500 light set for commuting, shop around and check systems out. As stated before, several very good brands including the one mentioned. Check spares availability for the battery and the bulbs. Many times the bulbs are special order. Consider the LED systems for reliability.

Tail lamps: Red blinky LEDs are great. But add a second one on your clothing, like on your back pack. Buy reflective clothing such as Illuminite. Remarkable visibility when headlamps hit them. I have a Platypus water hydration system t hat has a full length LED flashing light and a large reflective strip of material behind it. From the rear, it looks about 3" wide and about a foot long! I mean Ray Charles can see this thing.

I'll let the others chime on for the remainder of your questions.
Stay safe!
angela