Currently I just have the 24-105mm kit lens (with a 5dmkiii) my intention is to get the 100mm macro and then a wide angle, so not that heavy......I have always like the thought of the Benbo because its very flexible, ideal for macro work but I am not sure how stable it would be for landscapes
The setup I outlined (above) has the ability to articulate beyond what you see out of a basic tripod unit . . . not as flexible as the Benbo, but it is VERY stable.
Whatever you choose, keep 3 things in mind:
Maximum load weight (not a problem if you're not throwing a ton of supertelephoto glass on it)
Weight of tripod & head (it adds up quick when you're take into account the head and the tripod)
Minimum height (since you mentioned flexibility) -- the 4-section tripod's center shaft extends, then comes down as a boom, which allows for getting close to the ground if you need to.