I don't like the silver heat resistant board covers because you are more likely to be burned if you are doing fussy little things on them.
I have wanted a supersized ironing board for years, Last month, my DH came up with the solution. My large (plastic) folding table now has an ironing board cover I can put on it as needed. This is also the table I use for pin basting, so I did not want aything permanently attached. I took an oldish twin sized mattress pad, cut off the cheese clothy side panels and quilted it to a piece of garage sale uphostery canvas. I cut and finished the corners, then sewed all 4 sides with pockets to run cord through for fastening. It is not beautiful, but it is done and very useful.