I'd get a herd of corys goin dude. They are such cool fish. There are some many variations too. Other wise you might could get a plecostomus for algae, or maybe another catfish of some sort to pick up on spare food?
For sand aeration, you need something that will dig in the sand--cories are not going to do that. Once every couple of weeks, just stir the sand around with your fingers. Personally, I stir the sand and added MTS to my two sand tanks.