I did something similar, but I think simpler, to what CD did. I bought saddlebag supports off eBay and then headed over to Ace hardware to buy a small piece of sheet metal that I cut to fit the interior of my bags. Wrapped the metal in black duct tape to keep fingers safe (and make the inside of the bags look a little less ghetto), then drilled holes and mounted each bag with two u-bolts and saddle clamps. Total cost was right around $30.
Now: 2005 VT1100C
Then: 1998 VT750CD