Tripods are very tricky to choose from, what may work for someone else may not fit with your style. I suggest you pick a max price point, figure out max weight needed for your heaviest body and lens setup (and flash if you use one or plan to), and the look for smallest collapsable length for pack ability in travel on luggage. From there you can figure out if you want a center column, what type of leg locks, what kind of head. I recently got a vanguard Auctus plus 323 ct tripod for my LF setup, and it's very high quality that matches up to the bigger names such as gitzo and manfrotto at a more affordable price so don't be afraid to look into these smaller brands. If buying used get something that's more recent, there will be parts and less worry about wear and tear from previous users. There are a few tripods at my work that can't be fully repaired without getting another broken one for parts. The lightest tripod I have is the Tamarac zipshot, it's basically 3 tent poles and a ball head, very good for a smaller camera on relativly even ground as there isn't much leg adjustment.
