RFID and 3G + GPS

Projects General Guidance
1

Hello,

I need to monitor where (GPS) some people use an RFID card and obtain this Information via GSM / GPRS ..

I thought:

3g + GPS shield: http://www.cooking-hacks.com/index.php/3g-gprs-shield-for-arduino-3g-gps.html
and
grove 125khz rfid reader

But ..

Is this possible? This shield allows me use I2C ports of Arduino?
I see it communicates RX / TX (UART) ... pin 2 to 13 and A0 to A5 are free ?

references:
http://www.cooking-hacks.com/index.php/documentation/tutorials/arduino-3g-gprs-gsm-gps

thank you