Here's some websites where various SDIO devices that are supported by the SDIO-Linux stack can be purchased.
Atheros AR6001 WLAN Card - CardAccess, Inc.
http://www.cardaccess-inc.com/products/index.php?a=wireless_lan
Bluetooth Card - Any spec compliant Type-A card. Socket Communications seems to have dropped their card. Other vendors include pretec (www.pretec.com) Palm BT cards
are reported to also work.... read more
The SDIO-linux project patches and documentation are now
available for downloading. There are three file releases available
at the initial release. The documentation file release contains the SDIO stack functionality and APIs for developing with the SDIO stack.
The 2.6.10 file release contains patches and series file for the Linux 2.6.10 kernel.
The 2.6.18 file release contains patches and series file for the
Linux 2.6.18 kernel.