The ones from Wal Mart are pretty bright, and each one has 3 LEDs in it. I found they worked better than the single LED lights, as the chicks could see the light better.
Before I got those lights, I simply used a flashlight propped up in the coop. You could also try that, as they won't need...
To help train my chicks to return to a new coop at night, I use one of those neat Wal Mart stick-in LED lights. I have attached one right inside the coop door, so I can reach in and tap it on before dark. Once it gets dark outside and the chicks get restless, they see the light and go inside...