In reply to coolhand:
Decent ball-heads are pricey, doesn't seem to be much of a way round it. I've got a Gitzo GH2780QR, which I managed to get, plus an arca adaptor, for under £250. Its not perfect but its pretty good, the drag control is very good and there is no creep.
In my experience creep is often due to the connection to the camera, not the ball itself, so its worth getting that sorted first.