I agree with you wuyuanxu. X38 is so new & they command a premium. Some hardware reviews say that the X38 boards are like a porsche on handbrakes. Fluxity, I'm also thinking of getting a similar configuration such as yours.
If not the Infiniti Ninja Rev B Plus (which comes with fan) consider the ThermalRight Ultra 120 extreme or Ultima 90. The 90 is my favorite, easier mounting than the other 2 listed, and great performance, with light weight that almost meets Intel board loading advice.
