A bit of searching found the manufacturer data, digikey didn't have the best link for information. A link to the link is below, you have an ECWF cap according to digikey so click on characteristic data in this link and you will find it
Radial lead type capacitor specification list
I have not researched caps for this sort of application before so i cant make a informed recommendation for you but looks like you are on a good track for making a better decision than i can with what you have found so far. I will say though that the cap you have listed from digikey looks to be a particularly low value, 2.2 nF will likely not do much as it cant supply much energy. Basically the cap is place close to the switcher so the switching device will take current directly from the capacitor rather than through line inductance from your power supply. So the capacitor needs to supply the full current for say 50 ns. 140 A for 50ns is a fair amount of energy, its 0.000084 joules.
you can calculate the capacitor by seeing how much energy it can supply with this formula
E = 1/2 * U^2 * C
Where
E = Energy in capacitor in joules
U = Voltage in capacitor in volts
C = Capacitor capacitance in farads
So to match this energy if your voltage is to only drop by 2 volt you will need
42 uF
If a single cap will not do the job use multiple caps, nothing wrong with extra capacitance (except for inrush currents when you turn your car on)
Regarding lead length and resonant frequency, this just goes to show you how critical even very small inductance plays in your circuit
When doing this sort of thing i usually dont look at resonant frequency because you usually avoid resonance, i typically go for the smallest ESR and put it as close as possible to the switching device within 5 millimeters if possible (5 mm is just picked out of the air)
hahaha yea i knew adding a bit of gate resistance and capacitance would reduce your ringing but i didn't suggest it because you might just give up completely. Also as you have written if you are driving 140A you want a really quick turn on time due to heat and ideally you should fix the oscillation another way or you might blow up your mosfet again
It is a very good chance that the oscillations were killing your mosfets and seems to be confirmed because your current fet has survived with lower loads.
either way looks like your making progess on what is a relatively hard thing to design