What is wanted in Darfur is a benevolent warlord, a defender of the people who will rule them kindly and stand against the criminal syndicate that controls Sudan. Apparently, there's some oil to be exploited, so there might be an economic base to support a warlord and his army of retainers in the long run, especially if those who cry out for military action in Darfur will foot the bill for the initial conquest of the region. A few benefit concerts might go a long way toward funding the crusade to save Darfur.
As I see it, a well equipped division of soldiers of fortune and caring crusaders could secure the safety of the refugees from Darfur, occupy and secure their former homes, repatriate the displaced, and secure the entire region of Darfur against further attacks. A smaller force could continue to defend it and maintain internal order after the Republic of Darfur breaks away from Sudan. Thereafter, the principal concern would be the suppression of any competiing would be warlords within Darfur.
Darfur is poor, and its denizens are not capable of defending themselves from their government. Peacekeeping in that land will require a permanent security apparatus, and the mercenary king might just be the solution.