Should I pair our Motorola MG7700 with Eero or ASUS mesh?

Hello,

Just acquired a Motorola MG7700 for our 400 Mbps Xfinity service.  We will likely go higher but don't need gigabit yet.

We have one PC that must be ethernet-connected for work, and our home office is on the side of the house.  So the modem/router is tethered there, not centralized.  Previously we had XFi with a pod and still had spotty connections.  

I'm unsure how best to equalize connections throughout the house.  We are considering either the Eero's; the ASUS ZenWiFi XT8; or MoCa adapters (https://motorolanetwork.com/moca-adapters-for-ethernet-over-coax.html).  

The home does seem to be wired for ethernet, but plugging in a 5e cable doesn't seem to do anything.

Thank you for any help.  Not a sophisticated technician here.