I looked for the same info a year or so ago.
The best I found was that the Saito 1.25 has the same thread and outlet orientation as the YS110. I never came up with an "off the shelf" solution for any of the others - there was a link to a custom manufacturer but that route was going to cost more than a YS and Header (It was about $600 by memory).

I ended up buying an exhaust fitting for the Saito and purchasing a Hatori unit for a YS then "cutting and shutting" them together with the help of a hacksaw and brazing torch