Interfacing Arduino UNO with TFT LCD and WiFi Shield
I agree with Chris on this. The uno is limited where it comes to pins and and ram, you should probably look at a mega, or similar. 

As far as running both at once, i don't think it would be possible with the uno, with the ram limitations, as well as pin limitations, you'll be hard pressed to get them going at the same time, within the same sketch. 

While technically it is possible to use alternative pins, i doubt there will be enough unused pins to shift an entire shield over to on the Uno

If you're looking for a cheaper rout, you may look at adding a secondary Uno to run the wifi, and send any data you need displayed to the uno running the tft via serial coms.