2000 Chrysler Other Wont start

The drivers for the plug coils and the injectors are in the ECM. You need to check outputs to the coils. The 12 volts that go to the plugs on each coil and also on each injector. A noid light is for this purpose and they are available and relatively inexpensive at parts stores. They just plug in to the coil or injector plug and will flash when the motor is rotated if all is well

So I need to check the distributor and also check the injector plugs to make sure they are getting proper voltage to them. If the arent then should I start considering getting a new ecu?

Also the car is a 2000 Chrysler 300m and they have a history of catastrophic ecu failure.

You are correct the do have ecm problems. A lot of Chrysler products do. But still you should check for voltages at the coil packs and the injectors if youre sure you've got fuel. Remember that the voltage will only pulse while cranking or running