In addition, it also depends on your ISP. Some will let you replace their ONT with your own equipment, some will not. That will somewhat affect your potential equipment and configuration choices. How much WiFi coverage are you looking at? A small apartment or flat? A large dwelling in the hills with detached spaces? Is it replacing an existing network such as cabling, switches, etc or as an addition, with router/firewall, ONT, WiFi being the only additions?