If he buys the ball and socket mount, it looks like it comes with the bonus 3/8 to 5/8 adapter that would fit either of the two manfrotto stands that I had mentioned.
Whoops, didn't see the 3373 has a 3/8" tip these days (mine doesn't). Per B&H, the 3336 has only a 5/8" stud tip, so he'd need the rapid adapter with 3/8" tip.
Damnit, I get all confused when Bogen / Manfrotto keeps changing around the tips on their stands!