I have a Pilot Nieuport 28 in the building queue for electric conversion this fall. It's designed for a glow .40-.60. I have a Mega brushless 22/30/3 motor and 3.6:1 gearing to put in it, with 12 to 14 cells. I've run this setup across a few experts and Motocalc and all seem to agree that it will work fine. I had also considered the Endo motor for it, but everyone said that it wouldn't be enough, at around 400w out max.
I will lighten the airframe where I can, but there isn't a lot that I can do with the kit, aside from substituting thinner/lighter ply in some areas like the firewall and formers, and maybe some lighter balsa sheet.

Hope this helps.

Rick