I've been through the same thing.
I haver used REI and Ex Officio zip-offs and like both. The only caveat with zip-offs is finding ones that don't have a lot of bulk in the zipper area and creating some chafing and drag on your leg, which I find annoying. Some models get a little detail crazy and get heavier– typical UL gear challenge.
I just got some GoLite wind pants and they scare me a little– really thin, but they are light. I wish they made them in lighter colors– the black is too hot for summer sun and bug protection. My plan is to use them with running shorts with built in briefs as a height-of-summer set. Basically, the wind pants are CYA for cold mornings and light rain.
I have found running pants to be really great hiking pants. New Balance makes excellent ones as does Brooks, Nike, etc. I like the polyester models for the better feel and seem warmer on the skin than nylon. Of course I've found used ones for pennies.
The other alternative is to just carry light rain pants and wear short. A pair of Marmot Precip or similar rain pants are just a few ounces more than wind pants. There is that sun/bug protection thing with the rain pants option.
I have a round-to-it project to alter some long light pants with toggles so they can be rolled up to knicker length. They make lots of long sleeve shirts that way— a cloth tab and a button to keep the sleeve rolled up. Pants may need two tabs per leg to keep them neat and even.