Narrowing down Journal Theme look for

Hi there!
I’m assisting a enterprise produce an online, niche publication and am seeking at WordPress compatible magazine themes. My problem is there are a lot of journal themes and producers.

I would like to ask for advice on how to narrow down my research or I would welcome shared activities by other individuals who had to find a magazine topic. How they narrowed the research or arrived at their current topic? Or what theme assessment web-sites are most trustworthy?

I recognize everyone’s support and time on this challenge.