Deergrower - I know this is a very late reply to your question, but maybe you are still working on it. And maybe there are others who can profit from it as well.

I did a little research and found that Soybeans, Cow Peas and Peanuts are all good sources of protein for deer and will do well in sandy soil IF you get enough rain. That is always the unknown factor that makes or breaks any crop in sandy soil.

Make absolutely sure that you do a good soil test before planting. Take samples from several different areas of your food plot and get them tested by a qualified agency - perhaps your local soil conservation department. Add whatever soil-improving chemicals that they recommend and then plant your crop and pray for rain!