I have often setup similar devices for R&D at work, using Hostapd to create an AP using Pis internal WiFi and ethernet uplink. I find though that it's usually b

I have often setup similar devices for R&D at work, using Hostapd to create an AP using Pis internal WiFi and ethernet uplink. I find though that it's usually better to use an external WiFi device such as an Alfa. This should be fairly simple too so long as there's no arbitrary restriction on requiring wlan devices preventing you from using WiFi+Ethernet rather than Wifi+Wifi.