If I had been weight-weenie'ing when buying my Wabi, I would have chosen the Lightning frameset. If you're planning on 2+ hour rides, the Lightning's Columbus Spirit+Carbon fork combo would be a good option. Geometry plays an important role too, so it's worth considering that when frame shopping.

Even still, my 58cm Wabi Special comes in at 19lbs without trying too hard (swapping out the Brooks saddle would help).