What I recommend that you do are two things. First, consider the sort of thing you are going to be watching on it. If it is BD and you want to see all of the detail, here is a calculator you can use:
HDTV Viewing Distance Calculator + Guide | Articles - Digital Digest
If you are using a 1080p TV (which is what most currently are), if you have 20/20 vision, with a 60" TV, you have to be 7.8 feet from it to see all of the detail. Further away and you see less than all of the detail that is displayed. If your vision is better than 20/20, you will want to be further away, and if it is worse than 20/20, you will want to be closer. With a 70" TV, it is 9.1 feet; with an 80" TV, it is 10.4 feet.
Now, the other thing you should do is to go to a TV store, and vary the distance you are from a TV. Notice the size of the screen, and measure how far you are from it when it seems like the right size to you. Some people like a smaller screen than one in which they see all of the detail, and if that applies to you, then go with what you like.
However, most people, when buying a TV, do not later wish they had purchased one that is smaller. Most people wish they had gotten one that is larger.
Now, if you are planning on watching the TV from the far away kitchen, most likely you should buy the biggest TV you can afford that will physically fit on the wall.
Given the light situation, you probably want to go with an LCD TV that uses LED backlighting. And you will see the picture better if you close the curtains.
