Hi, Both cards come with the SD card reader. Which one do you recommend?
As an aside, if I use a Xbee card from another manufacturer, will there be interference or compatibility problem if I also use either of the shieds mentioned in the title at the same time?
The WiFi shield is a dedicated WiFi shield. It allows you to connect to an existing WiFi network.
The Wireless shield allows you to connect any kind of wireless device that uses a XBee footprint. That could be a traditional (radio) XBee, a bluetooth device, a Wifi device, or anything else that has an XBee footprint. The suitable WiFi devices are not restricted to joining an existing network. They include WiFi devices that can create an adHoc network.
The choice depends on what you want to do with the shield.