@pnjf,

According to my team, the units in the kits can both operate as satellite units, however we do not currently sell a Kit with only Wi-Fi nodes, nor individual nodes. You can upgrade beyond the AV1300 to other kits such as AV2000, but the speed will still be limited to that of the AV1300's. Since you already have a system that is compatible, I would recommend maybe looking into OneMesh. If you have a TP-Link router this would open a lot of doors for extending your network.