I sent my SCD-777ES SACD player out to Sony in Laredo Texas 7 or 8 years ago to have a new laser installed. I shipped it in the very flimsy factory box and packing it came in and Sony sent it back in a box for one of their receivers! While the receiver box was of a much heavier and sturdier cardboard, like Elizabeth said the original box was "a total steaming pile", the Styrofoam packing had completely disintegrated into tiny pieces of Styrofoam. Their box and packing had a lot to be desired.
I would go to a place like U Haul and purchase the proper sized box. I would buy 2 to double box. I would then buy a sheet of inch thick Styrofoam, line the bottom of box and all sides with it and one for the top. That should be more than sufficient. Also bubble wrap the player first.