What must a deacon be

Ivor Powell said in his book The Amazing Acts "Some leaders are apt to think they are the only instruments God can use and that, unless they are in charge of a project, it is doomed to failure before it begins. It is wise to recognize that other people have gifts and that all should be used in the administration of church business." The pastor is the one who will stand before God and give an account for his church but God has also given him a group of people specifically to help with the burden, that being the deacons.
As far as this passage of scripture we can't actually be dogmatic that this passage is dealing with the first deacon board, though that is my opinion. It could be that they were called upon for this specific purpose and it is just so that it mirrors the role that deacons play in church business. For the sake of argument we will look at this passage as if it is dealing with the creation of the office of the deacons.