I have a cheap solution. I got a journal cover to use with my Reader. The Reader doesn't fit snugly but fits well because you can insert the back of the original cover into the journal cover. However, I also have a removable cardboard insert with foam to make the Reader fit more snugly when transporting my Reader on a long trip in my carryons. I find it not inconvenient to use the Reader directly when in the journal cover on planes/trains.
So all in all, it's like a carrying a leather journal a bit larger than the Reader which itself is kept in the original cover. I think this provides adequate protection in my carryon.
And, I got the cover from Staples.