Look at the MCW5002 and apogee and especially WhiteWater. Very simple but effective. complicated doesn't mean better cooling.
Milling that last one will be a ball buster. The walls are so thin and adding bends will make it hard not cut throuigh a wall.
You have a decent design idea in the center. So keep the middle design but simplfy it with straight channels. The block will still look wickedly complicated and still be hard to mill wuth the tight tolerances
&
forget cutting all the channel on the perimeter of the block. It just reduces flow and gives no improvement in cooling. Just remove all the metal on the ouside.
http://www.cooling-masters.com/forum...showtopic=2993