^ Zebronics Diamond series are rebadged Skyhawk power supplies. They are quite decent, and nothing like the lower-end Zebby stuff. Quite a few members have used it with very high-end cards like the X1900 series.
In fact the Powersafe PSUs are sourced from L&C, the same company that makes the lower-end Zebby's (although Powersafe has better QC). Not sure who makes the new dual-rail Powersafe models though.
@jith: Funky had mentioned about availability of the HX520W models, but quite a few months back here :
http://www.techenclave.com/forums/go-corsair-620hx-modular-smps-84426-3.html#post543226
BTW, you should consider the NeoHE 500W (if available) over the TP 2 550W. Even their new EarthPower models look quite good and reasonably priced.