A couple of things...
1) I have a Kenmore 17741 and love, love, love it! It sounds so quiet and it'll sew through anything. My only gripe is that for some reason it now needs some help getting started (with the hand wheel) but it's not that big a deal.
2) I'm a teacher, and when kids write on the white board with Sharpie, we write over the marks with a dry-erase marker and then erase. That seems to remove it. Maybe that'll work for you.
3) I bought a sewing machine on the online Goodwill site, from the Goodwill in Hillsboro, OR. They packaged it really, really well. If you see a machine from there, give it a try! I also bought a Featherweight from the one in Ontario, CA, and I seem to think it was packaged pretty well, too. It didn't have a case, though.
Good luck!
Ila