We have some Sonoma fieldstone but not nearly enuf so we have to actually buy rocks. They are pretty cheap , its the labor that's the killer. Gluttons for punishment, we are seriously considering putting stone walls along the front of each terrace. It would lok great as we leave the driveway.
For cover crop I used 60% Blano Brom 40% subterrianian (sp ?) clover (tri color mix) I chose these because they are quick rootng, good erosion control, endure foot traffic, only grow 6-12" and are non invasive to the grapes. For fun I was going to alternate the rows with clover then Brom but at the last minute just mixed them all together. I'll probably do that with something else another time - I just wanted to get some erosion control in fast for this winter.
I'll post pictures as the rock walls progress.