I need some guidance purchasing a new single sim phone. I need a phone that i can install whatsapp on. Has to be from one of the following brands - Nokia, Sony Ericsson, Samsung and Micromax. Also the phone needs to be under 10K. A 5MP camera with flash prefered but not necessary. Qwerty keyboard and touch are also optional. I do need decent battery life and the phone should not give me problems. I use the phone for the following - Making calls, Sending SMS, Whatsapp/Chat, Internet Surfing, Listening to music and occasional photography. Please let me know of any good options available in the market.