The Apevia one is low-quality. The AZZA one is low-quality. The psu you currently have is low-quality. The Corsair CX is better than all of those, but it's still not even high quality. Remember, wattage isn't the one thing that determines a psu. It's all about the quality, as a low quality psu WILL fail on you and when it does, it will blow up and might destroy some components in your case.
That being said, this is a great high quality psu on a good price:
http://us.ncix.com/products/?sku=59615&vpn=P1550SXXB9&manufacture=XFX&promoid=1307
It will allow for any upgrades you wish to add to your build.