I've been shopping for stainless steel muffin pans and cookie sheets forever! I finally found some on-line, but the "really nice" muffin pan (tri-ply) costs $31.00!
We don't do much with muffins at the moment, but I too am using liners when I do. It is so hard to find anything that is not coated or made with aluminum! Sorry I wasn't any help - just thought I'd commiserate!