Hello David..

I'm prejudiced... I'd go with the Zenoah.

OTOH, I've never set eyes on the MVVS engine, so I've got nothing with which to make a comparision.

Performance wize, the G26 on a Sig Cub is a fine combo, but I'd for sure get it from Ralph at R/C Ignitions with his ignition setup and a pitts style rear muffler. Lighter, easier starts, better idle.

best of luck!