Plugs for '94 E150 5.8L

I just bought this van and wanted to change plugs and plug wires. On some Fords I've heard that only the Motorcraft plugs will work correctly, because of a slight difference in the size of the insulator. Is that the case with the '94 E150? I would like to use platinum plugs, if possible, to get the longest interval between changes. Is there a platinum alternative for my van.