Hello,
if you are not afraid of tweaking, you can install an open source firmware on certain router.
For example, "tomato usb", the version of toastman is perfect.
You can deploy it on some asus router.
QoS is consumming CPU, so be carefull, dig a lot on forums to find a model that fit your throughput.
Tomato Toastman's Releases
QOS Tutorial
If you want something more plug and play, I remember a new concept, but I cannot remember the name.
I will post if I find it...