We are slowly making progress, exams at the moment have meant we haven't had any spare time. However, we have found a suitable battery for the Raspberry Pi and 5V boost converter so they are on their way.
The datasheet from the wireless modules stated that they needed 12V @ 200mA. Opening them up revealed a 7805 voltage regulator, this works by drawing the current required by the circuit and wasting the excess energy as heat. By connecting the power after the voltage regulator we can waste less energy as very little will be wasted as heat and we can power them off 5V which we need to generate anyway.
This has simplified the design and the layout (at the moment can be seen below) Red indicates power, yellow indicates video signal.