Copy editing and line editing

I have a 65 page booklet that has 3 contributing authors, myself included; all of us have slightly different styles of writing. We've started a style sheet for some consistency, but it does not flow. We are looking for someone who can not only proof-read, but also help create a consistent writing style so some rewriting (minimal) will be necessary.
This booklet is one of 6 that we will be creating as support material for online programming (1st of 6 programs in production is launching mid-August), so hopefully we can use your services on-going...
Many thanks for your time.