My experience with saddle measurements has been that the width = the absolute widest part, which includes sloping sides. I have been able to line up a ruler underneath a saddle & edge of bottom to edge of bottom measured out to the advertised width. If your sit bones truly measure out to be 130 mm, then a 130 width would probably not be adequate to support you -- your sit bones would end up on the very edge of the downward slope. But you don't want to go too wide or you are apt to get rubbing friction. Sounds like 143 would be a place to start for you, but only if you are absolutely sure about the 130 measurement.