Bioballs are more trouble than its worth. Unless they are cleaned regularly, they will end up being a nitrate factory. Instead turn that area into a fuge! It will be much more beneficial for your tank too!
Also, i would suggest putting in a protein skimmer section and bubble trap
Cheato is the most common, and the best. You can get some from Bifferwine. She is out right now, but she should have more by the time you get your sump set up