QoS features on the Asus RT-N66U
Has proven a popular device, and while it does not have the AC WiFi of the others at £90-120 the price is a bit lower and your priority seemed to be wired rather than wireless.
The white version at £89.99
or the more traditional black router at £120
If you want maximum oomph and need the AC wireless then RG-AC66U
at £130 down from £200 has more WiFi speed and USB 3.0 support.
The Asus are popular because of the different WRT based firmware solutions available.
The archer c7 is a good budget choice, but generally have found the TP-Link web interface to be more old fashioned and less GUI based/friendly than the Asus.