CR18's are a little on the heavy side. They build up great, though.

I recently built a pair of wheels with Pacenti rims. I chose them for lighter weight. I haven't ridden them yet, so no report on durability or anything.

Velocity rims get good reviews. There are also other models of Sun rims, such as the M13 or some such. I think those are lighter than the CR18.

Velo Orange also makes handsome vintage-esque rims.