Caddison,
You might want to try something like I did, though I think your chain idea would work. I built a multifunction toolbar (not as neat as yours, but its what I had lying around!). To this toolbar, I added some brackets so I can attach the harrow you see in the pic. I can push or pull the harrow, so it works both ways, which is faster. I also can add one or two scarifier teeth to rip a trench.
Someday, I plan to add some more brackets so I can run 5 scarifier teeth to use as a ripper.
Note: The mutifunctional hunk of 2x4 has since been replaced by a metal bracket.