I think to be completely honest all churches have different views, my parish is pretty lax with what goes, a friend's parish is so strict on rules etc she ended up abandoning her christening ideas and doing something else to avoid the red tape if you know what I mean. Speak to the priest at your parish, get the low down from him, it really does seem to differ big time.
Personally I have 2 Godmothers and 1 Godfather, my son has 2 Godfathers, 1 Godmother - 'tradition' says the child should have 2 parents the same gender as the child and 1 of the opposite gender. Today though pretty much anything goes, just double check it's ok with your parish!!