Best Piston Rings for the Magnum??

Got a question: I have to buy rings for my build and I have pick between two different types.
Now I have an old gentleman who does my machine work telling me that the dodge small block do better with Iron piston rings and when I built my 74 D200 360 I listened and used a nice set of iron piston rings and have no complaints.
Well I'm shopping for a set of good rings for the Magnum 5.9 build and all I'm finding for the year of the block/Magnums is poly rings.... (Moly)
what should I use? Poly or iron... (Moly)
It will be efi and supercharged...

let me know if I'm being dumb for asking this but I just want to make the right chose.
Oh and I'm ready to buy now just waiting on all of you to chime in...

thanks