Hi Robert,
Most of the rolling stock shown in my video was scratch-built, in particular all the bogie freight wagons. We still have a fair number of people in the hobby over here who enjoy building from scratch and there are several suppliers of castings and parts suitable for this purpose. However there were also some kit-built items in the video too (brakevans) and some commercial RTR coal wagons.
As Andrew mentioned, Tenmille are a good source of varied goods wagon kits and of course Northern Finescale have an expanding and excellent range which are now available (in the UK at least) as kits or RTR.
Please contact me off-list if you would like any more info. I sometimes have stock of used wagons available.
Regards,
Geoff Calver, UK