That's pretty low. It might work, but you'll want more wiggle room. Plus you really don't want to cheap out on the power supply as it is the heart of your computer. I think a 550watt-600watt one would suffice.
Won't work most likely. the IBall PSU is poor and probably can't even output 450 watts. Look into
an EVGA b2/g2/gs, Antec, XFX, or SeaSonic 500-600 watts