You'll be lucky getting an 8gb SD card. 4gb is the largest you can get, and then it HAS to be a non-sdhc card. There is a place on ebay that sells them, at about £10 each. Search for rns-e non hc SD card.
If you're in a rush I'd look for a couple of 2gb ones instead as they're likely to be cheaper.
As for Bluetooth the xcarlink is as good as anything for about £100. Plus it might negate the need for small SD card.
Unfortunately this isn't a great solution, but the best oem solution would be quite a lot more money and parts sourcing would take a while.