aygent543 :
You dont have to worry about the Haswell compatibility that much. You can use any good PSU from Corsair, Seasonic etc. The above mentioned Seasonic S12II-520 will pump 40A on the 12V rail and if thats not enough you can try S12II-620 which has 48A on 12V.
Also, where is in Kerala ?
Any corsair PSU is not good
VS and
CX series series of PSU from corsair are poor for a for a gaming PC build with cheap capacitors and 520 watt is more than enough required for him even if he OC the card and CPU.
r9 270x max TDP 170 watt processor 84 watt other system 100 watt tops so 520 watt is more than enough and for the amps r9 270x requires 24 amps @ 12+ volt continuous current.