I'd go with the 18-135. Used in combo with the 100 macro, a DA 15 and 55-300 it covers pretty much every conceivable use and limits your lens changes in the field.
The IQ of the 18-135 is excellent centre sharp everywhere in it's focal length, and I hate lens changes, so going to 135 is important, and I use 135 on the 18-135 extensively, even as a pseudo macro because it focuses very close. For me, I'm just not giving that up.
A few recent K-3 images... from a bushwhack through some wilderness, trying to find a lake....
K-3 and DA 18-135
Pseudo macro at 135mm
Wide angle 18mm
This last one taken at 48mm
You have a wide angle shot taken at 18 and a couple close ups taken at 135... people will say you don't need the range. When I see some images taken with their shorter FL lenses I like as much as the ones I take at 135mm with this lens, I might listen.
For me I wouldn't wait for the 16-85, because it's not the lens I want. But, everyone is different.