I agree with Dave. I still love you Roman, but the B1 and rrs55 are great heads and capable of handling the 10+ pound lenses.

I use a Foba Supper Ballhead becuase they work great, the handles are very large so they can be opperated with thick padded gloves on, and you can pick them up on ebay for less than $250 with the dovetail plate! I really like mine! and decided to go with one after talking with a couple of my mentors about it (they both use the Foba).