Both should work fine, if you co with buckwheat watch your seeding rate, it can really shade out the ground. Also it will die after the first frost unlike the wheat. I personally like the grains for that application
Echoing what One Horn said, I would go with a cereal grain with the clover. We typically use oats and barley/rye. The oats will be toast about the time of rifle season, but it offers some good forage up until that point. The barley/rye will stay green all winter and offer some good forage in the early spring before everything else greens up. Rye can be a little tougher to deal with, since it can grow to 4-5' tall....we have switched to barley to offer early summer grain heads to the turkey hens and their poults.