Need help to buy right Phone among Samsung duos 7562, Xolo Q800 and Lenovo P777

Hi Friends,
I want to buy a phone in the range INR 10 to 12K . and finally i have isolated my search and choice to these 3 phones
Samsung Galaxy Duos S 7562
Xolo Q800
Lenovo P770.
My requirement is good internet speed on pphone for browsing, good camera,Document viewer and editor, Good music,Handy and in good colors(as i need it for my wife),good after sale service.
with samsung, i read that the phone hangs and internet speed is slow.
Xolo - after sale service is worst
Lenovo - is fine, but camera and music is not so good it seems.
SO please suggest!!!!

Thanks