Hello
you are looking someone wordpress expert for a wordpress website in make changes and update site as per your need so i will make the same as you want and we have develop so many website and also make the fully responsive design, please share us link of the existing site and changes.
having experience in Wordpress/Woocommerce, Wordpress theme/plugin /template development, Wordpress API, WordPress e-commerce sites, Bootstrap, HTML5, CSS3, PHP/MySql, all the CMS/Framework of PHP, Integrations/Customization of theme/plugins/API development.
I can easily do any type of development work according to your requirements.