Pioneer Churches Book Proofreading

I'm seeking a skilled proofreader for my book on pioneer churches. The primary focus will be on correcting grammar and spelling errors, but I also want someone who can help enhance overall readability and flow. The book will consist of histories of 70 parishes. The total number of words is appropriately 70,000 or about 100 pages.

Ideal Skills:
- Exceptional command of English grammar and spelling
- Experience in proofreading and editing manuscripts
- Ability to enhance readability and writing style

I am open to suggestions on which style guide to follow, but I would prefer someone with experience in editing for readability and writing style.