I'm planning a similar trip next year (From Boston to Spain
via the Azores). Sept/October is perhaps not a great time to be in that area since it is still hurricane
season. I'm planning on leaving late May/beginning June to avoid winter
gales and hopefully before the hurricane
I would recommend looking through John Kretschmer's website https://johnkretschmersailing.com/
and try to join his webinars. He just did a two part series on Atlantic crossings, with the first part focusing on West to East, and the second part East to West. Totally worth it.