Editing and Proofreading of a Literary book of 17.000 words

I need some help with the editing and proofreading of a horror book. The writing is not that difficult to understand and it was written by someone whose mother tongue is not English. We would appreciate if it was someone who had previous experience in editing and whose mother tongue actually is english in order to detect properly mistakes and lack of flow in the writing. The book is only 17.000 words long so we would expect someone to have it done by 2 weeks tops. Paying is by Paypal and can be done periodically since the book can be split in four parts of 5.000 words and paid accordingly each time. Any bid is appreciated, Gino.