I have a 7.1 setup of Aon 3 mains and Aon 2 surrounds with Forcefield 5. I'm upgrading to 11.2 with more Aon 2s and another FF5.

All the Aons are wall mounted right now with Omnimount 20.0W for the Aon 3s and 15.0W for the Aon 2s. It seems that the Omnimounts are now out of production, and I haven't been thrilled with them anyway (screws strip and they settle a bunch after you tighten them, so it's very hard to get them precisely angled). Plus I'm in a new place so might want to cieling mount some of the surrounds.

Are there any known good options for me to wall and ceiling mount the Aons? Searches of forums and Google have come up short of anything I feel confident in buying.

If you want to wall mount and angle them the universal brackets are the best choice. There are other vendors besides omnimount with products for this application. A quick look at Amazon showed multiple brands. Of course, if you don't need the swivel option, everything gets a lot easier as the Aons come with a keyhole mounting bracket for flat to the wall mounting.