Also consider how to prevent pinch flats. In my experience, the best defense against pinch flats is super-thick inner tubes (usually marketed as "thorn-resistant"). Liquid sealants aren't good for pinch flats, partly because pinch flats tend to be long slits instead of pinholes, and partly because one of the slits will be on the "belly" of the tube where liquid sealant doesn't reach it well (due to centrifugal force). With the added weight of the electric kit, pinch flats are more likely too.

So if I were going to make a suggestion, I'd say use a tire that has a good anti-puncture reputation, plus a thorn-resistant tube, and you can add a Mr. Tuffy-type liner or Slime (or both) for more protection.