I am not familiar with the Grummand but I have used steel studs in my build. I made my galley hatch frame from 1" square tubing. I also helped build a houseboat cabin using steel studs for commercial construction. Lots of advantages. I I were going to run wire through the wall, I would drill it out oversized and sleeve it with some brake tubing. to protect the wire. Use shrink wrap to give additional protection to the wire. Locktite has a new family of adhesives that seem very impressive for attaching siding to the steel.
Enjoy, Chris