Internal shifting hub recommendation for 80s mixte frame

[Gsinill]

Thinking about converting an old Motobecane Mixte from RD to an internal shifting rear hub (min 8s) along the lines of an SRAM G8/G9 or Shimano Alfine.
Does not need to have integrated braking since I will keep the existing rear brake.

I don't have the frame yet but it is an 80s model, so I assume it will have either 120 or 126mm spacing (or was that different for Mixtes?).

Any recommendations on a particular brand/model for this purpose?
Normally not a big SRAM fan but according to Sheldon B. the older ones were still designed by Sachs in the Vaterland so they must be good ;)

Thanks
GS

[Ken Robb]

If the bars on the mixte won't work with Mtn. Bike shifters you might use a barend shifter.