By what I've seen here, I think for the sake of discussion and objectivity, I'd say non-muslims would be better off if they stay out of this thread.
Now, this is all based on theory. Pakistan definitely would be able to give a lot. We have non-oil resources and have the strongest Muslim army in the world. We have know-how, we have technology and all we need is education for our poor and good leadership.
Turkey will no-doubt play an important role. About Iran... Iran has much to promise and I am sure will be most willing to contribute. They have the will but I am assuming that their tech is outdated and their military isn't very capable... or atleast, not as capable as Pak/Turkey. However, they have the oil and potential. GCC countries pose a big question mark. I would assume they are probably the least willing, and with Saudi leadership as it is, we must look for Muslim countries outside ME to lead. They will no doubt be an asset but right now they are not as close as they should be. Arab unity loosely revolves around Israel. This is not our objective. We want Islamic unity.
Right now the arabs are a big oil bank but I am sure if they shape up, they can get their act together. Even distribution of wealth around all Muslim countries is necessary. Right now Muslim wealth is polarized due to the fact that nobody is following Islamic financial laws.
As for soldiers themselves, might I add that the concept of Jihad on the battle field arms our soldiers with a psychological weapon greater than any gun or knife. May God help us all...