As far as lights go, you can get a P7 from dealextreme for about $30. Usually you will need batteries and a charger, but they run for about $15. The magicshine also gets a lot of praise.

For a rear light the Planet Bike SuperFlash is highly recommended, and with the 1watt version out is has gotten even better.

For cages they all seem to be about the same. I have the PowerGrips on all of my bikes and I like them a lot.