I can't tolerate the smell of the silver ones, and have known people who insist they are allergic to the coating and that it causes breathing problems for them. I have looked at all the instructions for making your own big board. Final decision is that I am in the process of making a removable cover for it. The last cover I made for the pointy ironing board was white denim with a few lines drawn with black magic marker as guidelines for pressing long seams that I did not want to be curved. This cover is a figured cotton, same weight as for patchwork. The board is 3/4" plywood cut to 18" X 60", well sanded and corners slightly curved. I covered the board with two layers of a thrift store wool blanket. I used an upholstery tool that has sharp nails that bite into the fabric so you can hold it tight while using a stapler or tacks. My husband loaned me one of his Arrow staplers that was easier on my wrists and hand than the shorter red stapler I bought with the upholstery kit years ago.
During my lifetime I have seen many old ironing boards that were padded only with two layers of wool, and some padded with batting. I hated the ones that had a thin layer of foam for padding. If two layers of wool proves inadequate, there is always the staple puller and a do-over.