Culing Cube is an excellent radiator. Combined with the Eheim 1048 pump, it will surely be enough for cooling the 152W peltier with no problem. I recommend you to use the MAZE2 waterblock from Dangerden as well. Although it's little pricey, it provides better cooling(not significantly though) and better install on mobo. (Uses 4 holes around the CPU socket.) I'm using the Cooling cube, MAZE2 block and Danner 500GPH currently but going back to Eheim 1048 due to noise. Eheim 1048 is almost noiseless.
Good luck.