A good website designer should know the answer to this one. Simply host your website (html or WordPress) using the SEO keyword domain and use Web Forwarding to point the branded domain to this site.
In 123-reg and when using our webhosting you can simply select the web forwarding option and select the branded name, for example www.fabbro.uk and fill in the “point to” to box with where it should go, e.g. www.goodfreelancewordpressdesigner.co.uk. By doing this any reference to www.fabbro.uk/thispage will then be forwarded to www.goodfreelancewordpressdesigner.co.uk/thispage etc.
Search engines will usually list only the hosting domain for keywords. The forwarded domain will be found and used, but usually when only looking for the brand words or the domain name itself, i.e. www.fabbro.uk will appear in searches for www.fabbro.uk