I was lucky enough for my g/f to gift me a Gitzo 2530 tripod! I am know at odds which head to go with. I am looking at a Really Right Stuff BH55, a Kirk BH-1 or a Bogen 468MGRC0. I plan on getting a 400mm Canon 'L' lens soon thus the reason for looking at the more expensive heads that are on the market. Any ideas/comments on the above choices, or any alternate suggestions? Thanks!