Arduino + Xbee + 3G

Hello! I did a project with Arduino LilyPad, Bluetooth and some sensors. Now, my new project requires Arduino and both communications 3G and Zigbee. So, the device receive data via Zigbee, and then it send this data via 3G to a smartphone (application Android).

Can I use Arduino UNO + 3G/GPRS SHIELD FOR ARDUINO (http://www.cooking-hacks.com/index.php/3g-gprs-shield-for-arduino-3g-gps.html) + XBEE for Arduino (what type?) ?

Arduino UNO has enough pins? Will I need multiplexor? Will I need Arduino Mega instead of Arduino UNO?

Actually, I am a little lost. Can somebody help me?

Thansk!

Alberto.

actually i stumbled on exactly what you need...
here's the link, enjoy 8)
http://imall.iteadstudio.com/development-platform/arduino/arduino-compatible-mainboard/im120411004.html

But I think I should use 3G, and that is GSM/GPRS. My project is:

(1) Arduino + GPS + ZigBee (mote)
(2) Arduino + ZigBee + 3G ("Gateway")
(3) Smartphone Android (application)

The GPS data of (1) is sent from (1) to (2) via ZigBee. Then, (2) sends that data received (GPS data of (1)) to (3) via 3G. Can I use GSM/GPRS for that instead of 3G? I have doubts. Enough bandwith?

Is easy to connect (2) and (3) via 3G or GSM/GPRS? How can I do it?

Any project like this?

Thanks!