I havent shot a sikh wedding but have attened many as a guess. The photographer in me says if I ever shot something like this you would need to have a second shooter, 2 would be ideal to be honest. There will far to much going on for you to cover it by yourself . Just keep that in mind when the subject of pricing comes up.
These are very colorfully affairs , as well as very religous , once in the Temple be prepared to wear a head covering ( bandana) hopefully your compfortable with that., there was a post a while back that the photg didnt want to wear one at a wedding like this, felt that the client was forcing their views on him etc.
be prepared for long days and be prepared for the bride and grooms parents to ordering you around
Again I have been to a few of these and seen it in action so beleive me I've seen it
Good Luck to you mate