western red cedar is kinda expensive - so is SYP(Southern yellow pine) - white wood seems to be fairly cheap yet i've been posting on FF(Foresty Forums) about trying to sell some 36"+ white oak logs seems the log market is in the dumps right now. couldnt tell it by the price for lumber thou
but yeah i'd use "western" red cedar for the siding and if you use wooden shingles i'd go with cedar too