SOP for a PhD in Finance for top US business schools

Hello, My future major is Ph.D. in Finance and I intended to apply to the top 20 schools in the USA (Chicago Booth, Berkeley, North Carolina & ...). I have written my SOP and sent it to my supervisor and... (Budget: £20 - £250 GBP, Jobs: Article Rewriting, Article Writing, Editing, Proofreading, Research Writing)