Instead of going with the newer strains of clover, go with an old established type, like Dutch White clover. It's more tolerant of PH, and spreads quite well on its own. Use annual Rye for a companion crop, It even grows fairly well in partial shade. Also if you can get back there a couple times a year and mow it, especially when it is in bloom you'll spred it even better (Mowing it is like hitting a guy with a chip on his shoulder, it will fight back)

Russ