My current one is 9 yrs old and is on the blink. I am looking at purchasing a new one from Apple. My TV is also about 9 years old. On the Apple web page there are 2 types, 4K and regular . Obviously, the 4K one is more expensive. Which should I purchase? I imagine my TV is not 4K. Would 4K work on my TV & would the picture be of a better definition? Thanks.