What would the best microphones be to record live bagpipes ?? one for the main chanter and one for the drones ? or just one mic placed in front ?
If you are recording in stereo, try a stereo pair of mics (models Beta 27 or SM81 or PGA81).
Read about stereo miking at: Microphone Techniques for Music - Studio Recording
If recording in mono, use just one of the models listed above. Then experiment with mic placement. There is no "best" mic and no "best" placement. Like in photography, there is no "best" camera" and no "best" lens. It all depends on the effect desired.