What sort of Christians are proponents of just war? Which sects of Christianity are support the idea of "Just War"? What are the arguments that they give that support this view? How do they see their views on this issue being related to the Bible?
The "Just War" is a concept very widely accepted by Christians - at least in the sense of acknowledging that there are conditions when Christians are called to fight. Catholics accept it, Anglicans do in principle (though some disagree), so do Lutherans, and many Baptists. They may not all agree on the conditions for fighting a 'just war', but they do generally agree that there are conditions when war might be legitimately fought. In fact it is much easier to list those churches that do not accept it.

Churches that believe it is wrong for a Christian to fight under any circumstances are mainly the historic Peace Churches. These are the Friends (Quakers), Brethren, and Anabaptists (which are comprised of Mennonites, Amish, and Hutterites). There are other specifically pacifist groups also.