Pot pie sized ceramic dishes were how I found out they work so very well. I don't know if the knock-off brands are down to that size yet, but I know Emile Henri makes them.

As for muffins, look into a silicone baking set. I find they're a HELL of a lot easier to maintain, and to work with than any metal set I've ever had. And cookies work well on a silicon pan liner, too. The silicon flexes, so the muffins stick less when you're getting them out, and also, it doesn't rust when run through the dishwasher. Although they do need to be set on a sheet pan when they're in the oven.