Exhaust system replacement

[750Yukon]

The time has come to replace my original 4 pipe set-up. Can anyone recommend a 4 into 1 set-up? Has anyone had any luck with aftermarket 4 pipe systems? Do they even exist. If it was at all possible I would like to retain the 4 pipe look. People's stories of things that didn't work would also be welcome.
Cheers

[JonnyB]

My '76 F has a Motad 4-1, thier website lists exhausts for the whole SOHC range, but the page title does say January 2002, so I 'm unsure if they still do them.

In case any one is interested the part numbers:
CB750K0-K6 (Sohc) M7H          
CB750F1      (Sohc) M7HF1          
CB750F2      (Sohc) M7HF2          
CB750K7      (Sohc) M7HK7S          
CB750KZ M7HKZ