I've installed revision B which uses several different components:

1. Pololu high current motor controller has replaced the Open Electrons version
2. Replaced the Raspberry Pi 2 with an A+
3. Removal of the Analog sensors, including current (this may be added back later)
4. Change in chassis
5. Replaced the 9Ah battery with a 2Ah battery (this only needs to last the Pi overnight)

Here's a shot of the inside of the chassis. The compass is likely going to have to get moved, I think there is too much EM interference in this enclosure.