All 117123 variations of motors are metal horned.
The plastic ones are lower wattage motors, you can
mount them together. ashbys used to fit one standard
and one high lift motor in the Ninjas.
I have run before now with one 117123-13 pulling
through a 116859, but performance is lower than using
2 x 117123s.
I wish I could find a source for the 1500w electros, as all
I ever see are the 1200w.