Since Didger no longer is among us, I'll take the role of recommending the Velbon Sherpa Pro "carmagne" series.
Sturdy and light, it's more than adequate for e.g. a 5D or 20D, 100-400mm @400mm and 1.4x TC (I haven't tested with heavier equipment, though Didger did some more extensive tests, do a forum search for Didger as author during 2004, and the text "velbon"). The IS on that lens isn't always behaving on a tripod (reported by several people, and unfortunately recently experienced by myself), so a stable tripod is rather important.
With your height, I guess it's the 700- or 800-series that would work best, the 600-series would require you to extend the center column. Like Gitzo, they're using collar leg locks for the 700- and 800-series. The 500- and 400-series also come with lever locks, like Bogen/Manfrotto.