While WordPress is great for blogging, it does have some critical limitations as an eCommerce platform. Sure there are plugins that give you all of the basic functionality, however, they are not nearly as robust as a true eCommerce script, and there are severe security risks in using WP for an eCommerce platform.
Another route might be to use a script built from the ground up to be a true eCommerce platform. The most popular shopping cart platform is Magento, it offers far more than any of the WP plugins and you can use it in place of WordPress, or alongside WP, just grab a plugin that integrates a WP blog into the web store.
