Your sand may be "sandier" than my sandy loam here, but I've had good luck with chicory, clover and oats. I've read that there is an Osceola variety of ladino clover(never used it personally) that does well on sandy soil. http://www.farmseeds.com/forages/clovers/ladino.html availabe here(pricey, you might want to shop around. I paid less than half their price for 50 lbs of patriot ladino.)

Go ahead and do the soil test now and apply any lime you need. It can take several months to raise the pH. The nutrient requirements will not change(well, very little).

Oats or winter wheat grow down there? If so plant 50 lbs acre with it to protect it from overgrazing while it is getting established. If doing oats alone double the rate.