With our Jrfueler, we use a 24 volt [ two 12 volts in series] remote battery pack, because we can have our crew guys start the motor, and then not have to carry the battery weight in the car. We just use a spray bottle to prime the motor, I perfer just alky so I don't color my plugs with gasoline. You may have a problem with not spinning the engine over fast enough. Also check with FIE or Hilborn about idle by-pass pressure. Also if your fuel tank/ line is too low, your FI pump may have a hard time pulling the fuel into the pump.
Hayden sells a 24 volt 10 lb battery pack, so even if you want/ need to keep the battery in the car, it's super light.
We need the 24 volt system because of the mag and the 16;1 high compression, and we just use a high performance 12 volt starter, with no problems for 8 years.
Jon, 800-624-3803, 805-444-4489, cell