My light of choice for this would be fresnels. Once again, I believe control is the issue. Although par cans would be adequate over much of the stage, the areas just in front of the screen would likely be washed by a par cans extraneous light. Fresnels would allow for a little more directional control of the light. In addition, fresnels allow one to manipulate and blend the light spread very easily.
Par cans require the changing of the entire lamp assembly or lens to change the spread.
The changed spread is from one fixed position to another, nothing in between. However, if PAR cans are what the budget allows, I would recommend using barn doors for increased light control. Before answering the last question, lets look at a possible light plot based upon the answers to our questions so far. The light plot, shown on the following page, is a possible graphic solution to the needs determined from our first two questions. For example, the answer to the first question shows that this church needs great flexibility in the positioning of various components for a worship service.