Have you tried the AmEx pre-approval page? It is generally pretty reliable. Double check the APR. If its a single diget (or small range) then you should be good to go. If its a wide range, then its a variable. As always, YMMV.
In my humble opinion, and i don't know why, BUT the higher AF card has a better chance approval, i would apply for the Aspire one which also has 100,000 SUB.
You can always check you score via the Experian website for free and that is the SAME EXACT score that AMEX uses.
Hope this helps.
You should be fine w/ an approval and a starting limit of 1k - 3k.
It appears Amex likes thin files and there are DPs of Amex Delta gold and ED getting approved w/ lower scores.
Personal Cards: Amex Plat | Amex Delta Res | CSR | Citi AA Exec Business Cards: Ink+ | Amex BGR