what does light in weight mean? tell us what tripod you have now.
i am using a cf benro (shameless chinese copy of gitzo, quite nice, i like it so far, with some minor reservations), it is not cheap, but a hell of a lot cheaper than anything else comparable. however, the ball head i have on those cf legs is so heavy, overall it's over 2kg anyway
. i don't mind though, and i love the head.
i used to have a velbon, alu, very nice, very cheap, decent head. not so versatile, but very stable, especially for the money. (sherpa 200r iirc), price was in the 150usd range (very cheap for what it is), weight in the 2kg range.
i can tell you more, but i am unsure what you are really looking for. more details please.