Ah I understand. Well the way things are right now, you can get away with a 250W psu, but I strongly support the choice of a 650W quality PSU. In the future if you decide to get a GPU, this PSU will hold any gpu you throw at it, so keep it. Overall a great choice. Even the case can easily hold the big liquid cooler.
Only thing I would note is - integrated GPU has limited amount of VRAM (1.72GB at most), which in big fights (raiding) might cause some hard spikes (havent tried raiding on my integrated HD530), so if it doesn't work you might consider adding a mid-range dedicated GPU.