Most CB's, switches etc., may not be able to be mounted in a thick panel without being flush or slightly depressed. Plastic has to be thick.
I do a lot of work with plexiglass with aircraft, and let me tell you it cracks easily especially when drilling it, and a panel requires a bunch of holes. If you go the plastic panel route
, use a step drill, not a normal twist drill. You can buy special bits for plastic but I've had the most luck with a step drill bit.
Also oversize you screw holes that mount the panel, properly sized holes and it will crack at the mounting hole, and leave the mounting screws a little loose, snug them up good and you will crack the panel.
Go with Aluminum and avoid the issues