Banneton/Frame/Pan Help

Hello, first post here!

Just started a new job at a place without much in the way of helpful baker equipment. They have nice connected bread pans, but nothing that has a width of more than 5 inches. The owner assumes I can crank out much wider (than 5 inches) bread, specifically for them to be able to make deli sandwiches, without him having to buy anything new. I've worked in an artisan bakery before that had these huge bannetons that held the 3 lb Levains used for sandwiches, and another place I worked used these rectangular metal frames that you'd put on perforated sheet pans, and had a width of probably at least 8 inches. I spent a good amount of time on the internet today and could not find any bread pans with a width higher than 5 inches, could not find any large bannetons, and was also out of luck trying to find any metal frames. I've hit a wall in trying to figure out this problem, and tomorrow I'm going to experiment using a metal sheet pan with about a 2 inch depth, to mimic the frame mentioned above. Does anyone know where I can get my hands on larger bannetons or metal frames? Or any other solution to creating a wide sandwich style bread? Would it be a waste of time to try it without any support before it goes into the oven? Thanks!