Jeff,
The issue I had regarding padding was scratching the painted finish, thus I believe padding is a good addition to any jig you may settle on. When you mention that you intend to build a bunch of Hobbycraft, Roden, and Italeri/Academy Nieuports that tells me you'll benefit a lot from using a jig. On my Aeroclub Jig I just put a bit of tape on the sharp edge or wrap it with a bit of paper towel and masking tape. I learned on the Brisfit (photos earlier) the need to pad the metal edges the hard way.... as you can see there's no padding there!
Cheers,
Lance