The rack on our Bio Bonatti truck was made by Voyager/Rover Racks. When they started out in the Pacific NW, I wasn't a big fan of their stuff, however they seem to have worked out their growing pains somewhat.
They were able to get a custom rack built for our truck on a relatively short timeline, and the rack looks pretty darn good (although to be fair, the rooflines on the Defender are a bit easier to match than on a Disco). My only complaints are as follows:
1. The rack came with a rough powdercoating finish. I prefer the smooth finish. Not sure if they'll do a smooth finish on request.
2. Our rack was damaged in transit, and had to be repaired. Voyager did a good job packaging the rack for transit, some moron at the shipping company was just overly enthusiastic with a forklift.