I just looked up a LifePo4 battery. Interesting battery.
ACR seems to be a good starting point. Would I be able to remove my dash electrical panel from the starting circuit, including the ignition?
No, the Helm the Helm is run from the motor, so "most" everything there connects thru the 10 pin motor harness
You could run a separate wires (+/-) from the house Bat up to Helm to run things like radio, fish finder, plotter, etc
If you do use a LikePO4 Bat than don't use a ACR and don't let your motor(s) charge in directly, it needs a special charger. The Bats are great and last a long time, but should be charged using shore power with specific charger type