You can get the VM26 Mikuni from
Sudco also. They are a legit company. I believe you may be able to order them custom set up for an additional charge. You want the link to the round slide carbs.
Standard setting as they sell them are here:
Note the VM26-8074 is a spigot mount carb, which would need an adapter to use.
Picture and parts diagram for the VM26-606:
You can order jets and other parts directly from them also. I use them as a source for my old Yamaha enduro work.