Redesign of a media wordpress website

The [login to view URL] website is basically a combinaison of two Wordpress installs (one for [login to view URL] and one for [login to view URL]). We are very satisfied with Wordpress and do not wan’t to change that anytime soon. We are looking for someone to help us redesign the personalised Wordpress theme that we're using. There is basically one index page, one page for pictures, one page for search and one page presenting an article. We have several structured data points for each article (on top of what Wordpress offers in standard): city, country, date, breaking news (flag). The structure of the website is entirely based on Wordpress tags. We’re using this beside categories. The index page is currently built depending on tags. The theme needs to be responsive, light (on both desktop and mobile), fast, suitable for mainly text-based articles (we do not produce or use much images; 100% of the article are pure text). We would like the look (especially on the main page). As you understood, our topic is art (contemporary but also tribal, antiques, etc.), so the look and feel need to elegant, neutral and simple. Some animation could be used but they should be light and do not overweight the website.