Input side…Can one explain what needs to be looked at when choosing an appropriate driver.
Based on this application note from MICROCHIP, on page 4 in the Design Example. It talks about choosing a driver based on the peak driver current requirement of the MOSFET, would the peak current be calculated as follows based on the MOSFET i have chosen,Total gate charge is easiest to use here, in the devices you have selected its 340 nC @10v per device, so if you want to turn each one on in say 100nS then its gate driver will have to supply 3.4 amps over that period; approx 10 amps total for all three.
As your switching frequency is low, circuit layout etc isn't so critical, you could use a single gate driver, look for one that can supply the required source current peak. The sink current rating of these drivers is generally higher that the source so they will be able to turn off your device in same or better time.