If you're going to be riding at night, use lights. It's incredibly unsafe not to and also illegal.
Regardless of what headlight or taillight you choose, I recommend having a second, even if it's not nearly as bright, as backup just in case something happens to the primary light. For the taillight, that means always running two lights as you might not know your main light went out. While I run a very powerful HID headlight, my backup is a simple 5 LED light intended to get me home if for some unpredicted reason my HID's battery dies. I've had to use it a few times and been very happy to have it.
Also note that depending on what state you live in, a rear reflector may be a legal requirement. I have one mounted on my bike that gets a lot of night use and while I doubt it does much, if I ever had to deal with law enforcement while riding at night, it will make my life much easier to be meeting all of the local requirements.