Thanks everyone.. Much appreciated, we booked Thai Airways.
Next piece of advice. We will be getting a car service from BKK to the JW Marriott as we get in at 9:25 and don't leave again till 2:30 the next day.
1. Is the VIP Immigration service worth it?
2. How much time should we plan on to get from the hotel 13miles away the next day through security at the airport and to our gate? Flight departure is 2:30pm.