I need a letter writing expert to assist with our direct marketing

I am looking for some help with our letter writing to prospective Clients in the commercial property sector. We have used templates in the past but looking for some help to create 3-4 templates that my support staff can use on a regular basis.

We use a combination of e-mail and letters and have only really had any benefit with the latter.

Open to other consulting down the line such as incorporating our deal and project data into our website etc.