Hi, I'm going to study abroad in Bangkok, Thailand and needed some recommondations for what some good airlines are. The ones I'm thinking about taking are either China, Thai, or Cathay. Also, I have a bad back, so going on this long flight is something I'm not looking forward to. Are there any airlines that offer like a lounge area to walk around or stretch out? Or would I have to go with first class for this?

Thanks,
David