Obviously the Order of Friars-Preachers fulfills this role in a consecrated fashion. Your best bet is to look at the Dominican Order from the viewpoint of Third Order laity. They are not consecrated brothers and sisters, but share in the spiritual family of St. Dominic. Primarily, the Order exists to study philosophy, theology, scripture, history, science, human events, and life in general, and to contemplate God in that study. Passing on the fruits of this philosophical and theological contemplation, specifically through preaching, is the very heart of the Order of Brothers Preachers.
As a secular/lay Dominican, I believe you would be able to live and preach wherever you like. It is the premiere lay-Catholic itinerant preaching institution, the Third Order of St. Dominic!