I don't know about metal lawn edging but Portland Nursery has a ton of supplies in addition to plants. You might try there.

Here is a link that might be useful: Portland Nursery

There's a fair amount of negative publicity on the Web about this material--mostly people getting cut. I would think that the top edge would be rolled or capped to prevent this.

Any little metal pieces in my yard get quite hot in the summer and I wouldn't want to inadvertently touch the metal edging bare knee-ed or bare handed, but then it's only supposed to stick up an inch above the ground.

larry_gene posted along the lines of what I shared with many customers, about the potential hazard, if someone has children.

It's a nice looking edge though. But it seems to look its best when its edge is flush with either the gravel or compost. And in most yards where I see it installed that precisely, the materials move over the edge to the other side.

Not sure whether you would like it or not, but there is one called Benda Board. Not Bender Board, but Benda Board or Bend-a-Board. Bend-a-BoIt's thicker, flexible and comes in 20' lengths that can roll into a car trunk. Sort of reddish brown. Definitely thicker though, and not the thin line of metal edging.

I'm not too worried about the dangers. I really want to use it to edge a brick landing that I have for my garbage cans and another brick area for some container plantings. The brick corners would be hard enough on knees and give enough of a warning that I don't think I'd have to worry about the neighbor's cat getting injured on it.