Upgrading Graphic Crad, Rs 11k Budget ($235-$245)

Hey guys, this is my first post here. I have read the sticky on how to ask for advice, and im doing my best to follow accordingly, please excuse my mistakes, and tell me so i can amend them in the future. Now to business. A very important thing you should know is i live in India, and im looking to buy EXCLUSIVELY from flipkart.com .
Im looking to buy a graphic card, around early July.
I have-
1) a 450W PSU, and a Zotac GT 520 2GB DDR3 (810Mhz engine/533 core/1600shader/1066 memory/48CUDA)
{ http://www.flipkart.com/zotac-nvidia-geforce-gt-520-2-g... }
2) an i7-2600 3.4Ghz 4 cores, 8 threads. Turbo goes to 3.7Ghz, 9MB Cache
3) Transcend 8GB DDR3 1333MHz RAM
4) an Intel DH67BL Motherboard.
5) the climate here is hot, so i would prefer NOT to overclock, but if i get one with great cooling, i wouldn't mind.
6) I have a 23.5" 1920x1080 monitor.
Now, as the title mentions, my budget is Rupees 11k($237). I can go maybe 11.5k ($245)
Im looking to play games such as BF3 and Crysis 2 at High(er)/Ultra Settings at (preferably) 1080p, but i can deal with 1600x900. Im a multiplayer enthusiast, so i like my games to work with atleast 40 FPS.
Now my thoughts- Getting a GTX 560, and selling my gt 520 to PhysX. I AM willing to get an AMD Card. Now i see i CAN get a 560ti, but i DON'T think my PSU will support it. I COULD also settle for a HD 6850/6970 IceQ , but again, the PSU doesnt seem to support it. Again, i look to but ONLY from flipkart.com . And before posting a link, please check to see if its in stock. Thank you guys.
Heres the link to:
HD 6870 IceQ - http://www.flipkart.com/his-amd-ati-radeon-hd-6870-iceq...