I have chaeto and calupera in my 125g fuge with some live rock for the pods
to hide and grow. In my cube I have just cheato for now. I use this light for my cube's fuge JBJ Nano-Glo
A cheaper and smaller option is 10W Underwater Light
The aquaclear 70 is a great filter to make into a fuge, search on utube for it and you can get detailed instructions on how to do it.