What sailboat is best for me?

I plan to circle the globe, and stopping in at every port possible. Ice is a big possibility so i need something that can handle that. I also plan on going through cape horn instead of taking the panama canal so i need something very seaworthy. I plan my voyage to last 3 to 4 years. It will be my wife and I (maybe some visitors) we want the boat to be very livable, and who knows maybe luxurious. I will have 650k to spend on this boat once my small one sells. Which boat is right for me?