i have found that what is on the website for free tickets (in A or W) is what other airlines have - AS doesnt have any special buckets for elites, etc.

i would just call both airlines and book a ticket - i think you can usually hold an award reservation for at least 24hrs (i think you get a week at DL), so call and have one put on hold, call and book the other one, then call back and confirm the original.

shouldnt be too hard...