You didn't indicate any limitations on budget, and if you can afford it, I'd suggest looking at Gitzo. I have two of them and they're about as close to bulletproof as I've found. There are also some other companies putting out reasonable quality carbon fiber tripods - Induro for example, and probably several others.
If budget is a concern, Gitzo may be unreasonable, but some of the other brands may have light units you'll like. The Manfrotto 055 is a decent tripod, though I'm not find of the flip locks rather than the twist ones on my Gitzos.
Whatever you get doesn't have to be HEAVY but it definitely needs to provide a very solid platform - otherwise it's just a very expensive paperweight.