Aluminum is not cooler than steel for a computer case. Aluminum is only lighter than steel.
The only caveat with the 3000B is the lack of window. For OCing, the 3000B has all the features you want. Side vents, front and back large fans.
Edit: I believe you can mount a 80mm fan on the side just behind the cpu duct. I am not positive however, but I do not see why you wouldnt be able to. However, If I were to use this case, i would have side exhaust for cpu. This would lessen the thermal burden of your case tremendously.
For windows, you could always make one yourself. Buy a pair of nibblers for < 15$ and as long as you have a drill that you can make a started 1/4" whole with, you are golden. Local Hardware shops sell plexi/acrylic. You could just use thin double stick tape and tape it from the inside of the case.