Hi,
Your requirement is not clear regarding the back-end requirement. We are interested in working on this project and invite you for a chat and detailed discussion.
CMS: Wordpress
Framework: Cake PHP, Yii, Codeignitor, Joomla
E-commerce: Woo Commerce, Zen Cart, OS Commerce, Open Cart, Magento
CRM: Sugar CRM, Suite CRM, Vtiger CRM, Zoho, Laravel
Other: HTML, CSS, PHP, jQuery