There is a enclosure from Adafruit, available in transparent (link), white and smoke
But not really a solution for buttons, you have only an open area not a good solution for buttons. Also the case is a bit week (you can twist it a bit).
If you find an other better solution, I'm interested also. I would love a enclosure for an Arduino optional with one shield, LCD and a 2x2 button pad like this one from Button Pad 2x2 - LED Compatible - COM-07836 - SparkFun Electronics