All of those are just as low quality and bad as each other, pretty much as bad as you can get in fact, I would not use any of them - Even if I was given a PC with one of those, I would replace it before I started using it. The power supply is the one part of a PC you should never cheap out on, always get a good brand such as XFX, Seasonic, FSP, Antec, Corsair.etc.
Notice how your current "500w" one only has 10amp on the +12v rail - This works out to 120w. A good power supply should output over 80% of its rated wattage on the +12v rail, yours only outputs 24%! Same with the Intex which despite being sold as 450w, also states that the total output power should not continuously exceed 200w. Not only do they not come close to outputting their rated power, I highly doubt that they have the proper protection circuitry that a good unit would have. If one of those fails (and it will), it is likely to take out other components with it. It is also possible for something to short out inside the system, a good unit would detect a fault and shut down, those cheap ones generally don't and can cause wires melting and fires.etc.
With power supplies, you really do get what you pay for. Don't risk it.
