The SK6 is not big enough to just drill and tap for direct mobo mounting. The reason I was wondering about this is simple, I hate clips. I've hated them for years. I was so happy when AMD required mobo manufacturers to use a standard direct mounting system.
I was thinking more along the lines of two 1/4" by 1/4" angle aluminum stock mounted to the 2 tabs on each side that the fan clips onto. These would extend out past the end of the HS out just past the 4 mobo mounting holes, connecting the two angle pieces would be just straight stock with holes in the corresponding places to do the nylon nut, bolt & spring thing. Now there's nowhere to mount the fan clips, but that's easy - two holes on each side, on the angle aluminum next to where they were originally.
Does this make sense?