Yeah well, looks and nostalgia aside, the Honda brakes (which do look remarkably like those Sanglas brakes) were rubbish, and there were guys here and in Britain doing front end swaps to retro-fit conventional disc brake arrangements back on to their bikes, at the time.
The biggest problem I see with this now is that it's a compromise limited by the size of the disc that you can use. (due to the hub size, which is restricted by the rim dia) Most modern bikes need discs around 12 inches in dia to pull them up with 4 or 6 piston calipers, so to do that with this system you'd need a hub with at least a half an inch all the way around the disc for clearance for disc mounting flanges etc, so the ID of the hub would need to be around 14 inches, then add another inch to the OD of the spoke flanges, and you've got a "hub" around 16 inches in dia, with tiny spokes to lace it up to the 18" or 19" rim.
Of course you can use smaller discs and calipers to reduce hub size (and braking ability) to try to get the aesthetics right, but you will still end up with a massive hub, with massive unsprung weight problems, not to mention serious brake over heating by taking the discs out of the cool air stream that conventional discs normally enjoy.
As far as 4LS brakes go, they were really good in their day against other drum braked bikes, but crap compared to a disc. I had a Suzuki GT750J (first model "water buffalo") with the 4LS brakes at the same time as I had my GS1000S with pretty basic twin disc set up, and the disc braked bike would pull up 30 feet shorter from 60 MPH than the 4LS set up. The 4LS brakes look great, but no good if you've just plowed up the arse of a car fitted with modern brakes. Suzuki changed from 4LS brakes to twin discs with the next model, the GT750K, my all time favorite Buffalo. Cheers, Terry.