Hello, i understand your concerns about security and testing(code review). I can say that i'm very professional, my education has been in computer science in the best univesity in Portugal.
So i'm not just a coder/developer, i'm a engineer so it's normal to thing about escalability, security, responsivness, etc.. in a web application.
I don't charge a lot of money so i'm open to negotiations considering the complexity of the project, but i really want to help.
Best regards, Miguel