Best place for submersible lights or suction cup lights?

[ravensgate]

I've been hunting the internet for a few days and about the only luck I'm finding are overseas sellers on Ebay. I'm looking for either suction cup lights to put on the inside of a lid (lights are on the bottom of this aquarium instead of in lid) or for submersible small lights (maybe 6-8 inches long). It's for a 3 gallon tank so I can't have anything too terribly large, would just like more light. I've looked at Walmart and Petsmart online but couldn't find anything. Thanks in advance!