Looking for advice on bus service between Kochi & Bangalore

Hey Good people of Kochi, wish you all a merry Christmas. I am visiting my in laws here in kochi for Christmas and am planning to travel back to Bengaluru sometime early January. Was planning to take a flight as usual but the prices seem unrealistic, so planning on taking a bus or train, given I won't find a seat this late on a train or KSRTC bus, I am hoping to book a private bus to Bengaluru. Could people suggest some good service and share some experience/ reviews on what to expect. New to town and new to bus travel. Thanks Kochi, hope you all have a great new year.