clover vs buckwheat

I may overseed my field peas with a late cover crop to benefit the bees. In your opinion, what would you use? I'm thinking either clover (white or red) or buckwheat.
What advantage would either have?

Clover honey tastes better... :)

I've heard that bees can't get the pollen out of the red clover because the tube is too long/skinny to access. So, we've been planting white clover for our bees.