Bioballs are really suited best for FO setups, or maybe certain FOWLRs. A reef setup should stay away from bioballs.
Bioballs are supposed to act like LR, handling bio filtration. Bioballs are actually so efficient at converting ammonias and nitrites that nitrates can build up fairly quickly - not necessarily a good thing. LR is slower, but it's deep pores also contain the bacteria that will also take care of the nitrates. Using LR, in appropriate amounts, is usually the way to go with a tank.
Comparing fuges to bioballs is apples and oranges. A fuge is a place to grow macros for nutrient export and perhaps a haven for pods and other critters.
Let your LR and a good skimmer do the work. Bioballs won't be necessary. You can add supplemental items like fuges and UV filters if you like, but they aren't necessary.
On that note, I might suggest going a bit larger with your skimmer if possible. You have the CSS65 on a 65? I would try to get a CSS120 - going over a bit is usually the way to go.
HTH
Good luck.