Don't be shy. Go ahead and fire away with the questions. That's what this forum is here for.
Technically, this is a nothing-to-electric conversion, not a glow to electric, so it belongs right here.
Usually when you go to electrify a plane, you start out with the battery since it's the source of the plane's power. Motor's usually near the bottom of the list. The AXi 4120/14 just might do it, though you may need more oomph, a higher cell count, so a 4130/16 or 4130/20 might be in order. 4120/14s are limited to about 16 cells or 5S LiPoly, and 40A continuous. You'll have about 650-750 Watts to work with.
A few details about the plane would help. How much does it weigh now? At 50 Watts per pound, you can go up to about 14 pounds, maybe 15 pounds, or 7Kg, on a sailplane. That's total with battery and motor, so your plane will have to weigh somewhat less than that without electric gear.
How much performance are you looking for? 50 Watts per pound will give you nice sedate climbs. I assume you're not trying to fly a giant hotliner here.