Thanks!
I will probably go with the factory heat range as well, being that the car will still have the stock snail and down pipe, and only have minor bolt-ons and a Strat 93 tune (and possibly a Strat E30 map as well) by the time of changing the plugs (planning on doing this at ~15K miles).
I also use this car year 'round, in ALL conditions and sometimes (regrettably) must use it for very short trips, so colder plugs could hurt me more than help, even in the heat of summer.