Depending on what type of night race you are doing you will basicaly need only lights. On the bike and on your helmet. The reason for lights on the helmet is that you dont always look where you ride and visa versa.

The only issue with light are, as will most of our cycling equipment, is that if you want a proper set of lights it could be expensive.

And of course a set of clear glases to keep sand and wind out of your eyes.