Hello,
I have a couple of tested SDrive boards for sale. It's my SMD recreation of the original SDrive http://raster.infos.cz/atari/hw/sdrive/sdriveen.htm
The only change is that is lacks DIP switch so the drive ID is hardwired to D1 and the write protect is directly connected to the SD slot. I believe most people don't need it anyway.
The price is 25 EUR plus 5 EUR worldwide shipping.
There are only limited number of the boards and I'm not going to make another ones.