There are kits available for this conversion. I would post a link to the one I found but they are not a vandor here so I can't. Sorry.
I can say that the kit is $259.95 and includes the bracket, bolts and 11 1/4" rotors. The calipers, pads, hoses and park brake cable extension are extra.
All total about $700.
I might be cheaper and easier to swap the rear axle. What do you do with you rango?(Off-road, Daily Driver,Race truck) is it 4x4? what gear ratio do you have? the reason i ask is so i could tell you what axles i would look for. the durango's stocks axles arent that great if you are doing anything other than daily driving, with out mods anyway. but this would give you a change to go to a stronger axle lower or high gear ratio, plus you can get your Disc brakes out back. Hope this was some help.
The rear axle on the 2003 Durango has disc brakes and from what I've read it's a pretty easy swap. I believe the only thing that needs minor modification is the emergency brake cable which is pretty straight forward.