George Marsden has two biographies of Jonathan Edwards, one quite significantly larger than the other. Both are worthwhile.
On Hus, Matthew Spinka, John Hus: A Biography (Westport: Greenwood Press, 1968)
On Wycliffe, G. R. Evans, John Wyclif: Myth and Reality (Downers Grove: IVP Academic, 2005)
On Zwingli, Huldrych Zwingli: His Life and Work (Philadelphia: Fortress Press, 1986)
On Farel, it's not a biography as such, but has biographical information: Jason Zuidema and Theodore Van Raalte, Early French Reform (Farnham: Ashgate, 2011).