Morning. I bought a Nest Wifi Router and used it as an access point. This didn't increase the wifi range enough even though it was only approx. 3 metres away from the outdoor camera. I tried to put the Superhub 2 into Modem Mode but couldn't get this to work. I read reviews of routers and the TP LInk C4000 got good reviews. I bought it from Ebuyer as they had stock, price was the cheapest, also free next day delivery. Amazon sells them also but at the time didn't have stock. I must say that Assus routers get good reviews on here but I have no first hand experience of them. The TP Link works a treat and has, so far, been faultless and I can highly recommend it.
I wanted to upgrade the Superhub 2 to 3 but the good JBrennand advised me against this. He also helped me to follow the correct sequence for connecting the TP Link to the Superhub using the TP Link as the router. I had tried to use the TP Link as an access point but it wasn't very good.
Best of luck to you.