Recessed Electrical Receptacles

In the process of constructing a dedicated audio room with AC power supplied by a 60A Torus Power Transformer. We will be running the AC power to hospital grade receptacles in the floor. Looking for a good solution for the mounting box and top cover which is big enough to accommodate two to three Shunyata power cables (typical boxes are too small to allow for you to plug in two cables together). These boxes will be mounted in the floor and recessed. Anyone have a suggestion or two? Thank you