hi
i would also target around 25'000 rpm. a good tuned zenoah does bout that.
those cars are geared very high so you need a high torque motor. the 30er lehners seem to be about right or the plettenberg
bolido. there also the pinions fit directly on the 10mm shaft.
a schulze 40.160 should do the job. if the promised XXL schulze 40.300 come out soon (?) those would be even nicer. i havn't converted one of my FGs yet but personally i would also do some kind of small watercooling circuit as there is some much room in those cars.
bye
rhylsadar