The light kit is composed of:
Two 21 LED lights ($5 each on EBAY, each uses 3 AAA rechargeable batteries (Nicads 1,100)
Went to an auto parts store and bought 4 sets of oversized rubber O-rings (about the size of a CD), it was about $4.00 total.
Each flash light lasts about four 2 hour rides but I usually give it a partial recharge weekly although many say it is bad for the batteries. I have done it for a long time and have not affected the battery recharge memory.
The twenty dollar or so Bike Lights DIY has worked great, they are water proof, none of the LEDs have gone bad, lights are super cheap and are extremely bright.
Because its at night I do not go that aggressive on hills.
Usually is Stony Point, Roblair Rd, Valley Ford, Spring Hill or Chilleno depending on the mood and the local bugs, all the way back via Western or D Street.
Its mostly a 25 to 35 mile ride, rolling hills A/B range, almost no traffic. The only scary thing is cows that could be in the middle of the road.