I don't think it will fit in this case. The case is only 5.5 inches wide, leaving less than 1/4 inch on each side of the Reader. You need at least 6 inches of width, more with side hinges. I prefer this case:
https://www.mobileread.com/forums/showthread.php?t=11420 , but then I made it. I suppose a thicker case could provide more cushioning, but I wanted thin. Mine is protected by an inch of paper in by briefcase. Not to be morbid, but where are you planning to go with your Reader that indicates an armored case is needed?