Before you settle on the Raspberry, have a look at the Odroid H2+
It has twin NIC and a Celeron CPU. I've only done a brief latency test but its better than my J1900 using Tommy's Mint 19.3 install.
The 2 Gb NIC though needs a driver installed as its very new. I just followed the link on the Odroid wiki and placed the driver on a USB stick and it was real simple from there.
In my experience a lot of Wifi issues are due to crappy WAP on home grade router. Now I've upgraded to a enterprise grade Dlink DSR500 router I find wifi to my machine much more reliable.
