What Spark plugs and external temp sensor

Hello all,

I am trying to service my jeep, one of my jobs is new spark plugs. I have a 2000 4.0 auto, I have read on the forum that the best spark plug is the RC12ECC, however people say if you have a vehicle with no distrobouter you should not use the RC12ECC, is this correct and if so what should I use?

Also my external temperature sensor is always reading 0, is it easy to replace and if so what is part number?

Thanks.