I need 2 build a E-commerce website in a month or so n confused about which platform should I use..
I have been developing with WordPress since 1 year, and have created a couple of eCommerce websites on WordPress. You can use WP-eCommerce by GetShopped to make things faster and easier.
Magento is also a good option but what I found annoying is that they don't have proper documentation about the modules or I should say they don't actually have it.
For NetChillies we are using the custom plugin we made for the same. It was a 30-35 hours job developing the eCommerce plugin and associating it with WordPress.
Moreover, look what you are comfortable with and start developing, should there need any kind of help am always there :)