Have you looked at time4learning, not a stand alone curriculum but we really like their math, the explanations seem to be very thorough. DS4 is working on this independently in lieu of taking naps (always negotiating) and has been able to cover first grade math in about a 6 weeks with very little parent involvement.
The software is definitely not quiet though as it uses, at least on the lower level, lots of animations to explain things. Maybe headphones would resolve that issue. There also appears to be a way for teachers to assign work to students although this module is not available to us.
Good luck, I'm sure others will have lots of suggestions.
-guy
