Issues in recording a choir:
1. If the choir has very bad dynamics, good luck doing a live stereo recording session.
2. Are they gonna follow a conductor? A minusone? If they need playback, you need a crapload of headphones, which is not very common in most studios. If you decide to use a wedge for playback, pumping out the right amount of volume to the wedge for the choir to hear will eventually give you bleed issues. Can be good or bad.
3. Multiple mics per section is good. Individual mics are best if you wanna automate each voice to death. (Nag choir ka pa.)