i havent used the iridium plug, 'cause like ghosto said, i don't think they'll be enough of a difference to justify it.
i've had best results with the standard NGK B7HS and the B6HS. i tried a BP7HS which is longer ("P" stands for "projected insulator",) and for some reason my bike didn't like it. it was harder to start and sputtered at top speed.
i run a B7HS in my main bike, 'cause it has a colder heat range (with NGK, the higher the number the colder the plug.) i run my bike at full throttle all the time, and colder plugs work better with high RPMs.
for wires, i buy 7mm copper core, non resistance wire, terminals and boots in bulk and make my own.