I'm not sure what you can or can't use, it's up to you really. I have chamomile, lemon mint, lemon balm, cilantro, anise hyssop, bergamot.......clover. Tons of clover.
Once your plants grow the canopy won't allow light to penetrate down and the cover crop will probably die off. And the cycle begins. You can also use your plant after harvest as part of the cover mulch adding more nutrients back into the soil and food for worms. The cycle of life for the no till garden