I used 20 AWG
Mike I have recently finished installing that module in my 8. I used 20 AWG wire for the power and contactor leads, as I am building my own harnesses. I had similar concerns about the low current rating of the recommended breaker and contacted the manufacturer. He stated that the module would handle 5-7 amps but that they had found the lower rating to be adequate. I am at work right now and do not have figures at hand but as I recall my contactor will draw around 4 amps at 12 volts so I plan to use a 5 amp breaker.
He also said some people use a continuous duty contactor, i.e. a battery contactor, for starting purposes. Those contactors have a higher resistance and draw much less but may not hold well as voltage drops under the starter load. I do not plan on doing this.
Chuck