@hdo: you might have a look at:
Yes, it’s not cheap but it is rock solid and has a super wifi performance on both wifi modules. I am using this configuration since November 2016 with quite a few (about 25) IoT, iOS, Android and Windows devices connected per wifi. Also, a workstation and a Sonos sound system are connected per LAN. I never had a signal drop out, connectivity issues or similar instabilities.