Funny you should ask. Night flying is becoming quit popular and here are some links that might help you out.
http://www.ecubedrc.com/lighting_systems.htm
http://www.flightlites.com/
also you can build you own system if you are so inclined
http://www.lsdiodes.com/shop/index.php?main_page=page_4
There are are more sites out there just do a Google search.
Two clubs here just recently had night flight fun flys and it was a fun thing to watch.
The best planes I thought were the ones with transparent mono cote and bright LEDs shining through. Also the slow fryers were fun to watch.