I've received a ton of emails and I decided to post the details here. I used the Step Flash to make the Magnetic Boards.
I purchased the Step Flash at Lowe's in the roofing department. Here's a picture. It's galvanized and it comes in the 5 x7 size. I bought it myself and I can walk you right to it.
My advice is to go to the store yourself. If you call them more than likely you will encounter someone that doesn't know. I went to Lowes and Home Depot twice.....I was looking in the AC dept but they're in the roofing department and I only found them at Lowes.
p.s. I'm not supposed to post other store names on my blog....but I continue to receive a ton of emails. Hopefully this will clear up any confusion.