Wifi + GSM connectivity

Hi guys,
I have to develop a project where I have to send some data to internet. I'have available a wifi network but, in some circumstances (i.e. power failure lost), the wifi network could be not more available, so I'll need a second way to access to Internet (I was thinking in GSM).
Do I have any shield available that provides Wifi access and GSM?

No. They are separate shields.