While it won't help with what resorts are offering AP discounts, the Mousesavers website has a listing of historical/current discounts. It really helps (but is not perfect), in gauging WHEN a discount will be available. The list of resorts that usually don't get discounts, stated above is pretty consistent/accurate. Since the general public discount usually comes out first I start there. What we've done in the past (and in fact for our June trip coming up....

) is we look at the where we'd like to stay..........get comfortable with that selection.
The key is being comfortable with the potential of NO DISCOUNT. We'll book our room before the discount comes out (this is a new strategy because of losing out on a room because I waited

). I then check the availability of discounts at the moment they come out (yeah I'm a discount stalker ). If I see something good I adjust my room reservation online, although sometimes I do call Disney

When the AP discounts come out a week or two later.............I go back in............and review again.
Sometimes my initial resort selection doesn't have anything in the room type I've reserved........sometimes it does. For our June trip, we originally had a room at the WL............it wasn't a standard so I was paying a bit more than I wanted. When the AP discount came out I reviewed other resorts and I found a room at the YC for less than what I was paying at WL. So I took it. For this trip our YC price came to about $280/night with the AP room only discount. My wife and I were very pleased..........the only adjustment to our plans was we will now "just visit" WL during our afternoon break at the MK.
The point here is flexibility and persistence. Now some people don't wish to be discount stalkers..........that's fine. Also room discounts are not the only/primary reason we have the AP. We're doing 24 WDW days in the AP year so we're saving money, at least in our minds.
To the OP, how ever it goes hope you get what your looking for and have a great Disney vacation!!