So the silicone mats arrived and they are slightly larger than my biggest sheet pan. The mats are 19.7 inches x 11.8 inches. I am guessing I need 20 x 12 at a minimum though a little bigger would be fine, but I am clueless as to what sizes baking sheets come in really and where to find them at a reasonable price. Anyone in the US can steer me in the right direction, please (also recommended brands/materials are welcome).
I went with the Nordic Ware 21 x 15 pans, I got 2 of them. I think
TastyReuben stated that he has this brand and they cleanup well. I read a review stating that they are not dishwasher safe and are prone to staining, and it's best to use them with silicone mats to avoid that...since that's one of the reasons I wanted them, it's a win win!