Seafoam is a multi-use engine cleaner product. Check their website. It's full of good info. Should be able to get it at pretty much any local parts place.
I went with regular copper NGK plugs in my 2006 4.7 and it loves them. Surely if your local shop doesn't stock them they can get them in??
06-08 chrome clads w/33" Cooper Discoverer H/T Plus, Mopar tailgate spoiler, debadged door trim & tailgate emblems, 13" antenna, LED dome & maps, Magnaflow 22" SI/DO, 18% tint, "HEMI" hood spears, VHT tinted tails & third brake light, Lamin-x optic blue fogs, leveled w/McGaughys 2" drop shackles.