I'd suggest not getting a hard plastic case, as that may cause heat issues. Also increases the bulk of the unit.
As for cases - I'd suggest a sleeve, and then a bag of some sort. InCase makes/made some very good neoprene sleeves (Similar to this Incase Products). Only some stores still have stock, as the 13" has been discontinued it seems.
As for cases - I'd suggest a sleeve, and then a bag of some sort. InCase makes/made some very good neoprene sleeves (Similar to this Incase Products). Only some stores still have stock, as the 13" has been discontinued it seems.