no you wont need to tell ntl, get one of
these.
If you need help after installing this then let us know, if you could let us know the model numbers of the kit you have already bought that will help too
And don't fret moving from usb to ethernet will be great for you and very easy. You might not feel like it now but its much better and this forum has seen hundreds through this process and we will get you online as required.
assuming you bought the right bits already