It does kinda suck that they don't include a cooler on the K or X especially since they are both such expensive chips, but I can not think of the last time I used any stock Intel cooler, thats what the Silver Arrow and Armageddon are for:D
As for the triple slot coolers on those Matrix 580's they will not work for tri-sli, at best you can use two cards and I feel your pain, that sucks:(