Well, DX11 may be released in end of july to August and in India they might be available after three weeks. Do you want to wait till then? Also, the games you have mentioned can be played at good settings using ATI 790G chipset. So, here is my recommendation :

AMD Phenom II X2 550 BE -> 5.2k or if you wait a bit more X3 740 will be available

Biostar TA790GX 128M ( AM3+ if you want to use DDR3 or AM2+ if you want DDR2 ) ->6k (AM3+) / 5k (AM2+)

Corsair xms2(DDR2) 2 X 2GB RAM or xms3(DDR3) 2X1GB -> 3k

Corsair VX450 SMPS -> 4k

Cabinet :: Cooler Master Elite series starting from 1.7k or If you want a local one then Zebronics Bijli for 1.2k

UPS :: APC 650VA -> 3.5k

Keyboard Mouse :: This should be your choice. However I prefer Logitech products.

So 22k-23k without Keyboard & Mouse.