All of them are good pumps but it depends on how many rads and water blocks you are using. For one radiator, a CPU block with or without a GPU block the Phobya or the Laing DDC will do. If you are using more than one rad, a CPU block and cooling more than one GPU then i'd grab the MCP655 vario or the Alphacool VPP655 as it's called above, same thing just a different label.
The advantage of 655 over the other two though is you can adjust the speed of the 655 so if you find it noisy you can turn it down but you can't do that with the Phobya or DDC.