As I pointed out in my previous reply you have as many options as you want. Sky's the limit. Do anything you like. Only bit you have to do is turn up at amphur with the required bits of paper, sign the paper pay 20 baht or whatever it is now, get the paper, leave.
Of course depending on the office you may require witnesses of your own, translators etc. The office will tell you what you need.
I fortunately did not require to bring anyone else as the office staff did all that- they even took a photo with my camera. We didn't have any sort of party after as she had no family nearby.
Soooo, have a gigantic party with monks and elephants or just a few friends over. It is, up to you.