Cardbus USB 64bit drivers Are there any Cardbus expresscards with USB 2.0 or 3.0 ports (one or more) that is compatible with the current Mac OS X (Mavericks 10.9.4)? This most likely mean the card has 64bit kernel drivers.

Some cards that might be compatible are the "Apiotek COMBO EC-0002C" that has one USB port and 2 Firewire. http://eshop.macsales.com/item/Apiotek/EC0002C/

and also the "Sonnet Allegro USB 3.0" which has two USB 3.0 ports. http://eshop.macsales.com/item/Sonnet%20Technologies/USB32PME34/

but I'm skeptical.

The Allegro while interesting is pretty expensive, especially as my main use will be a simple external keyboard. The existing 2 USB ports in my old Macbook Pro is used by a MIDI controller and my Audio Interface and I have been warned against USB 3.0 for those, so this additional ports will be for other stuff I need to connect, like the keyboard and my iPhone.

An USB 2.0 expresscard with one or two ports would be nice. Are there any that are actually tested with the current OS X?
The driverless "Apiotek COMBO EC-0002C" http://eshop.macsales.com/item/Apiotek/EC0002C/ does indeed work great if you still have a Cardbus port. I have not tried with Yosemite.