Proofreading and editing on an academic journal

I have a written journal paper. It needs to be cleaned up in terms of language also needs to be edited. It might even need re-writing. It needs to be done until the end of February at the latest since I have to submit it in March. I have some specifications on the person whom I will work with. The proofreader should have a background in a computer science area, s/he should use overleaf, and should hold a PhD.