My colleague is correct. I recommend that you retain counsel to assist with the process to assure it goes smoothly. Since we are nearby and have an office in Tampa, we would be pleased to assist. If you choose to go elsewhere, that is fine. I would recommend though that you hire an attorney who is a member of AILA, the American Immigration Lawyers Association.
Yes, you can apply starting September 2013. Please remember that it really helps to have an Immigration Lawyer help you because it's not just the application, but a lot of complex rules you have to qualify for. Let an immigration lawyer take the worry away, and make the smoothest process possible. I am also in Tampa if you need me. Emel Ersan-449-4422
This is only a short advice- you should not file anything without getting the full facts from a lawyer.