If you can afford it go with the non-ultralight version. The clamp is just that much better & easier to use. They sell a shop/commercial version of the clamp because mechanics like it so much better than other varieties...my shop has gradually replaced every one of their old clamps with the Feedback one.
Sit bones = ~135 mm, saddles that work ~ 155cm/6.1 in wide
2003 da Vinci (custom road/all-rounder)/Terry Butterfly Ti
1994 Gary Fisher Nirvana (vintage MTB/commuter)/Terry Butterfly Chromoly
1991 Terry Symmetry (NOS frame/fork, project in progress)
1973 Raleigh Super Course (project in progress)