As mentioned, google any of these manufacturers: J R Smith, Josam, Wade, Geberit, Zurn. There are dozens of models available, and you plumber will need to determine what is needed to work with your wall construction and waste pipe configuration. Are you going to use a tank-type toilet? Seems you would not have the mandatory 1" water supply for a flushometer type.
Success. I found a Wade carrier that will fit the stud width and typical bolt pattern. Thanks Again!