Web Development - Wordpress or similar

A client of ours has an existing web-site which they are largely satisfied with the design of. What however is totally user unfriendly is the bespoke platform on which it is built. We would like to explore the possibility of switching this extensive site to wordpress or similar to make integration with hubspot and content management easier in the future.. We will provide details of the existing site to freelance candidates. Staffordshire or Midlands UK base a preference