Pretty hard to get hold of made up sailboard pads these days. You can buy SUP deck grip kits and cut it into shape but it's expensive.
Just for under the footstraps... like a "normal" size and not to do the whole board?
If so, the bin at local WS shop. Like the junk tradeins etc
Just slice it off the board slowly slowly with a scalpel as you peel it up gently. They come off with no dmage if you're careful and then Kik Grip it onto your board.
You might even get a snapped board for $20 and get pads and 3 or 4 straps too.
Just contact a boardmaker and see if they'll sell you a set. You could try OES or Stone, that's how I got some.
i bought some from the states from these guys had them with in a week cost about $70aus been using them for a couple of season now and their awesome haven't tried a better pad yet on a custom board tons of grip
www.northshoreinc.com/store/pc/msg.asp?message=95