I'm around 5'9" and have a 3 series Gitzo. With my RRS BH-55 head it is generally tall enough with about 2-3 inches to spare on level ground.
The question is how often you need a taller tripod? I find that streams, hills, and birds in flight are the main occasions for a taller tripod. But the Gitzo XLS models do not easily collapse and fit in my normal suitcase, so I compromised with the LS. The XLS is certainly heavier - which for me is a bit of an issue. So I am currently considering a second tripod and would relegate my 3 series to use for air travel only.
The suggested Feisol legs are a good option. I've heard nothing but good comments about the Feisol legs and the offer good value.