Sir,
I am 15yo experienced designer, programmer and videomaker, at the same time I have 10 employees in my team. I have more than 100 websites in my portfolio and I use to develop from small companies to big industries. In these 15 years, I worked for a long list of companies and I have some projects like you are asking for. All websites that I developed have a complete content manager and a friendly mobile version.
My skills: HTML5, CSS3, SEO Experience, PHP, MYSQL, Graphic Design and Video Edition.
Best regards,
GUSTAVO