What model of NGK spark plugs should i use if i haven an PerTronix Ignition Kit with new coil and electric fuel pump installed in my 1972 240z?

Should i strive for NGK-R spark plugs?

The only important part here is the coil. If your coil is hotter than stock, you can use the wide-gap version of the stock plugs. I ran BP6ES-11 with Pertronix and a Crane PS-20 coil.

I just upgraded to NGK (7133) BPR6ES-11 and have a Pertronix...I run much better now. Its more the spark plug gap than the plug in this case. The old points needed a smaller gap, where as the electronic ignition fires best with a wider gap.