Best ones are as usual Msi Twin Frozer 3, Asus DCU2, or Gigabyte Windforce or sparkle artic cooler, or Powercolour Vortex.
All these have dual fans and special circuits, vram, pcb, etc. They are a lot quieter than reference designs.
Oh and whats the price of 7970 in India? Just curious because I'm from Mumbai now living in the US
If you are now living in the us why are you wondering what the price is in India? :S