Hi Dan
I wouldn't bother to go with an onboard glow yet if it was me. I've run lots of inverted glow engines in the past and have never needed to. I would try it without and then if you do have issues that can't be solved with proper tuning, then consider it later.
The main issue with inverted 2 strokes is with starting, as if it is too wet it can put the glow plug out and even hydraulic lock if it's really wet. Starting with the model upside down or on its side with the exhaust down makes this easier. On board glow obviously does not help with this!