Spark plugs.

I hear the groans already and im sorry to post this. But im a new BMW owner just over from the school of honda and im not new to the idea of car mods but as ive never done european i found the forum for my car and figured id hit up the pros. Now i have just ordered my K&N filter and some light body modifications and i was hoping you could point out the best exhausts and possibly a header and a chip for my 1995 bmw 318i also what are the best spark plugs available for my motor. i looked for iridium ngk's but they dont seem to carry them for the m42. any suggestions guys? thanks !