Best company for Night sleeper ferry to Koh Tao from Surat Thani?

Hi Community,

Me and my wife are going to be travelling to Koh Tao, via a sleeper ferry from Surat Thani. I saw that there are different ferry companies? if this is case which company is better and do you have any tips for the ride? I read somewhere that it can be very cold...

Thank you much appreciated