If you’re not sure what your tripod options are, then check out OutbackPhoto’s field report on the subject. I use a Gitzo G2228, which looks similar to the Explorer shown on the site, but I use a Manfrotto 555B offset center column, which puts what I’d call a half ballhead below the tripod head, which makes it a breeze to level the head. I also use the RRS BH55 ballhead they mention on the site.
wow, talk about a surprise when I checked the price of the G2228.
I think my whole tripod setup (tripod, center column and ballhead) ended up costing me around a grand.
I got all the stuff from ReallyRightStuff.com. George Lepp had the exact same setup and let me use it for a few days… after that I was hooked and bought one before flying home. It was a gift to myself… splurging on one of my passions.