hi
A vehicle Ignition coil draws approx 3 to 4 amps from a 12V battery supply.
In circuit #1, depending upon the value of R3, a 5V MCU output pin may not be able to drive the Darlington pair into saturation.
You also MUST consider some form of back emf snubber for the transistors,
On circuit 2, the 5V from the MCU must drive the MOSFET into saturation, also back emf protection is required,
Regarding just switching the driver ON/OFF, remember that the EHT spark is produced when the driver is turned OFF,
You must also allow sufficient ON time for the driver [dwell time[ to ensure the coil current has reached its maximum value.
E