I have a 1999 xcab 4x4 4L OHV that I have owned for about a year. I want to replace the plugs, wires, and coil. I know it’s not a race car and therefore doesn’t require unobtanium spark plugs, but I don’t want to go with the cheapest stuff either. I’m looking to get as much performance as I can (I realize I won’t pick up an extra 40HP). My question is about spark plugs, which should I go with? Iridium, double platinum? Thanks.