Is there anyone on the Coast who does this?
Sometimes the honest answer is that the nearest is in Christchurch or Nelson, and the quote should say so with travel in it. NovaPay asks locally first and tells you when it has had to look further rather than quietly widening the search.
How is it priced?
Usually a rate for a set number of hours, plus travel and sometimes gear hire. Ask what happens if the night runs long, since overtime is charged and is easier to agree beforehand.
Can I choose the music?
Most will take a must-play and a do-not-play list and read the room in between, which is the part you are paying for. A DJ who will only play your list is not really being used.
Do they bring the sound system?
Usually, though some venues have their own and some have sound limits or curfews. Say the venue in your request, because it changes what is needed and what is allowed.
How far ahead should I book?
For a wedding or anything in December, months. Weekend dates go first, so give the date early and you will have more to choose from.