Just buy a water proof container with a trans parent lid. Anything with a rating of IP65, IP66, or IP67 will be plenty good.
NEMX 4x Enclosures and Boxes - PN Series | Bud Industries
Of course you cutting holes in it will compromise things.
I would recommend installing water proof IP66 buttons (just google) and using IP66 rated wire glands to run wires in and out.