Just a note on complete Zuiko kits. There are actually two distinct kits in the focal length range under 100mm.
"The OM System Lens Handbook" in the discussion about the 40mm F2 says, "Differences in visual effects begin to appear at 1.4 times the focal length. For example, going from a 50mm standard lens to a wide angle, such effects first appear with a 35mm lens - that is, 50mm divided by 1.4. What that means is that when a picture taken by a 40mm lens and one by a 50mm lens are seen separately, it is hard to distinguish one from the other."
So, that convinced me that the 40mm is in one "kit" and the 50mm is in the other "kit."
Kit 1: 16mm, 20mm, 28mm, 40mm, 55mm, 85mm
Kit 2: 18mm, 24mm, 35mm, 50mm, ?, 100mm
One way to remember what Kit 1 would be is aperture values (2 -> 20mm, 2.8 -> 28mm, 4 -> 40mm, 5.6 -> 55mm, and 8 -> 85mm). Get those lenses, and you are set for a wide variety of focal lengths. Same with Kit 2.
Maybe this was all widely known by everybody but me, but I just found it out this weekend. I found it enlightening, and helpful.