I was happy with my Giotto's MH1000 ballhead. It is relatively cheap and has a nice sturdy metal ball that locks very effectively. I also had a Bogen/Manfrotto (I forget the number) with a plastic ball and it did not lock well enough for my taste. I have found the same to be the case with the grip action ball heads from Bogen. You do have a lighter rig than the Mamiya 645 I was using on it, however, so you might do better. I know that a lot of folks swear by their grip action bogen. (Sounds like a GI Joe doll. )