Nice that you are in the count down mode for retirement.
Welcome to the forums. The more you read and the more rallys you attend to look at Airstreams in person and talk to owners, the more you will learn about what is the best TV and Airstream for you.
It is easy to buy new, especially if you have saved the money, but I recommend that you buy a used trailer in excellent condition. Trailers are really quite simple. There is really not that much difference between a 10 year old trailer, well cared for and a new trailer. Buying used will allow you to try out the Airstream that you think is good for you. Later, if you choose to buy new one for whatever reason, then go for it. But test the water first, before jumping in with both feet.