used 16-35 or new 16-35 II?

Did you not read the OP?

Again, he listed his gear, he is reasonably covered. Has two fast lenses (50 1.4, 135f2), has a normal zoom (24-105 which can do kind of macro), has a tele zoom, has good flashes...

Only thing doesn't see to have is UWA which is the point of the post as he seems to have identified the specific thing he is looking for...