Given a choice of 5 people, I would insist on having two programming minds on the case, A systems analyst to operate at the level of designer and project lead. A tester and a system documentor. Do a half-arsed effort on documentation and you will dread the whole exercise.
On programmers, I would of course ensure that the system is clearly defined and have set out the tasks for each programmer. Having two or three minds looking at the same programming problem enhances the programming effort and could speed up the exercise in general.
The system analyst will in my opinion be driving this, hence full control of the plan should lie with him/her. Project milestones, etc should me controlled by this person. Testers and documenters would shadow the work of the programmer(s) and the analyst.
Not forgetting the application "owner" who should be available at all levels to assist the programming effort.