None of the DRAM 'NEEDs' a cooling fan, most might coole an extra 2-3 degrees, but modern DDR3 seldon really gets hot, except those with low freq and high DRAM voltage like many of the 1600 1.65 sets.
As far as the 4770K, may not want to OC now but a year or so down the road, might come in handy, plus it's not hard, in fact to OC to 4GHz, basically is just a simple change of the multiplier