if there is enough availability on the AA flights, there's a trick that Ive used and can confirm works. (you can check availability by trying to book 4 or 5 award seats for those days and times and see if it allows you to)
Once you make the ticket with AA using miles, it is free to change the dates and and times of the ticket as long as the airports and passenger names stay the same. So what i do is book a ticket for the airports i want for any day greater than 21 days. Then once the tickets are "ticketed" (you will get an email) call AA and change the tickets to the dates you want for free (even to today's date!) that would save you the fees for less than 21 days.
As far as Starwood transfer times, Ive never transferred to AA...sorry