I don't know how I managed to miss this one so far since it's designed and built by Mike Burrows of Burrows Engineering who are just up the road from me in Rackheath near Norwich. Unfortunately I couldn't find a website but Burrows are on 01603 721700.
I finally found it via the very useful Bikebiz website with extra information from Bikefix (the only dealer I located), Velovision and Fisher Outdoor Leisure.
As you can see the 8 Freight has it's 21x24 inch cargo space behind the saddle. It runs on 20 inch wheels and transmission is 8 speed SRAM. The frame is aluminium making the 8 Freight light for it's size.
The standard version with its large canvas load bag costs £1250 from Bikefix but specials can be ordered with load areas to suit your needs.