Electric or mechanical water pump/ electic pump questions

Hello all

I am looking at fitting an electric water pump and after some advice.

The engine is a high comp (14/1 ratio) 493ci big block (Fully forged, trick flow heads, holley sniper efi system) that will only be used on the stripe.

Is a electric pump needed or will a high flow mechanism pump be ok??

What Gallon per min would pump will need to flow??

I will be running a thermostat spacers as need 2 ports to read temp (one for gauges other for efi system) does an electric pump need to be running for these to read the temp??

Would I need a thermostat whqt every option I choose. As I want to run braided AN lines and unable to find a water neck that will accommodate a mopar thermostat?