What are the best options for rock, for french drains?
That's a pain, but I think the standard advice for outdoor french drains applies. 3/4-inch minus rock and def filter or landscape fabric (not the plastic kind, the woven kind). But from a quick bit of browsing, you might want to layer filter fabric down first then rock then a socked pipe (keep the sediment from even getting to the rock, like an outside french drain.

You are going to get some sediment in your sump bin. Just make it large enough to justify the work and perhaps be able to get a secondary backup sump in there comfortably (either a battery back up or water). 

Not quite the building code information you were seeking, but it does sound a lot like you would benefit from thinking this is an outside drain in clay soil.

https://www.ndspro.com/french-drain-installation