Can you please confirm that your respective offices can process the required 400 visas for the 3 of you?
Otherwise if needed, I can put you in contact with our visa agent in Perth who will be able to process your visas once payment has been made.
But if you are fine doing it with your respective offices, please let me know and I will send the 400 visa request letters to you.
In that case, I will need passport copies for each of you (I have one for Narongsak already), confirmation of home entities and confirmation of position titles.
Please note that proof of accommodation is not required for 400 visa applications so we will be able to get our Travel department to make a booking once your 400 visas have been approved.