HairyScot: Thanks for all the info.
Looks like the first step is a new router. Maybe a Draytek (depending on price of the model that has the facilities I'm after) or one that is Gargoyle compatible.
Anyone has any experience of Tomato Firmware?
I've used tomato for the past 3-4 years... currently I am using the Tomato (Toastman) version, which has per IP logging that works great.
It has QOS and a bandwidth limiter which is what you are after.
Love love love tomato