You're referring to a Midlite, Panamax, etc pair of j-boxes with power inlet and surge protection? If it's new construction, you shouldn't need that- you can use a power inlet at the rack and run whatever cabling needed (Romex, BX, separate wires in conduit).

I have one in my van and will post a photo of the packaging- I use them when I want to power a TV from the same surge protection device that is used by the rest of the system- all I need to connect it is an IEC power cord and it's not only legal, it's much less expensive. Use whatever kind of box you want- a Decora plate fits over it.