Sorry, I was reading from my phone and missed that you've got Ethernet. In that case, consider Sonic's mesh solution but with the wired units instead of the wireless ones. You can mix and match any configuration via our member tools, give it a look:https://members.sonic.net/equipment/order
I just spent a minute with the tool to see how you'd configure this, and it's a bit wonky. The "minimum" order is one of the starter kits, but none are simply two wired units. But, just add any starter kit, then add two wired units ala carte, then remove the starter kit - as long as you've got two units and at least one of them is a base unit, it's satisfied.
(And I'll talk to team about making the cart behavior allow for this.)