Advice for buying Xbee module

Hi guys,
I want to build a small 4 wheels rover controlled using wireless xbee modules.
I’ve never used these modules before and I’ve only read guides on internet so I would like to order the right components to write and test my personal sketch for the whole project. The components shipping is from USA to Europe so it’s important to buy all the basic components I need for future testing.
Which Hardware do i need? I was thinking to buy:
-2x Xbee Module (2mW series 2) – I thought I’d take the series 2 because it consumes less and is newer that series 1, let me know if I’m wrong. XBee 2mW Wire Antenna - Series 2 (ZigBee Mesh) - WRL-10414 - SparkFun Electronics
-2x Arduino – Arduino n.1 in the transmitter and Arduino n.2 in the receiver
-1x Explorer USB – to configure xbee settings SparkFun XBee Explorer USB - WRL-11812 - SparkFun Electronics
-Other accessories (such as: USB cable, Breakout Board for XBee Module and headers)
How do I configure xbee modules?
I was thinking to set them up for serial communication; for example:
Arduino n.1 read an input (from button or joystick) and send a message to Arduino n.2 that receive the it and do something (control motors to go forward or backward…).
I’ve already build a mini robot (with Arduino) that moves along the room thanks to ultrasonic sensor that measures distances to obstacles and walls.