Once the ATMega168 arrives with all the other stuff, you need to program it with the motor controller code. Either make your own code, or use/modify the code below.
You can make a very cheap ATMega168 programmer, or buy an AVRISP MK2:http://search.digikey.com/scripts/DkSearch/dksus.dll?Cat=2621880&k=avrisp
And download the free AVR Studio development environment:http://www.atmel.com/dyn/products/tools_card.asp?tool_id=2725
The hex file of the code is available here. Use "coug-unified-16k.hex":http://www.adambrunette.com/firmware/cougar-v1.11b/hexfiles-m168/
Here's the code:http://ecomodder.com/wiki/index.php/Open_ReVolt/Software
The fuse bits are Extended High Low = F8 DC F7. But if you are using Ponyprog, the fuse bits are 08 DC F7.
If you don't want to bother to program it yourself, then you can buy a preprogrammed one.