I would not recommend er4 and er6 unless you have a lot bigger user base, 200 upwards clients for example. Even er-x is already overkill for many home users. Trust me that includes myself. In this case er-x is perfect for you. Er-x can do 1gbit internet connection and not break a sweat.

From my experience using er-lite for over 4 years. The router never need to reboot at all. 100% no hangs since i bought it in 2016. Same thing with most of the forumers in this thread that i help since i post this tutorial (almost 70-80% own er-x). The only time the router restart is because of electricity trip or lost and when i do a firmware update every year.