oh boy the bioball debate. today it seems like it's fashionable to hate on bio balls. people say they crash tanks and holds poo and whatnot, but Ive seen those people's tanks, and lets face it, poor husbandry is causing their problems, not pieces of plastic. they are not a substitute to live rock, but the guys that complain their sumps are loud cause the water is crashing through the now vacant trickle.....put the bio balls back in and clean them once a month. I would go that route.
the sand, pretty much sand is sand, Ive seen builds that guys throw the play sand in their tanks, i wouldn't go crazy like that, but im sure that sand is fine.