You are not going to like this. If you want pretty lies [that in the long run will cause you problems], stop reading now, and hope someone with a different mindset replies.
Your room, as is, is very poor for this. First of all, you have too much light coming in; you even have sunlight hitting directly where you say the TV is! It does not get worse than that for light. You also have what appear to be very [acoustically] reflective surfaces everywhere; most of the time, such an environment is extremely poor for audio. A more acoustically dead room is usually far superior to an acoustically live room. For the audio, you will want curtains, carpets, soft furniture, and anything else like that to help keep you from having echos. And any kind of echo will make it harder to understand the dialog when watching a movie.
As for speakers, I am unfamiliar with the particular models you mention, but for the front, you want the speakers to be at about ear level when watching things, so definitely not in the ceiling. For the center front, it should ideally be the same height, and as close as possible to the screen; the ideal would be with the center speaker in the center of the screen itself, though that is not possible with most TVs. For the rear, such things matter far less, so you can get away with ceiling speakers if you must.
For the subwoofer, for such a huge open space, you will need something quite impressive if you want actual depth (or volume) to your bass. Polk is not where I would be looking for this; SVS is the company I would probably go with, though others will likely give you some other recommendations for different brands. But this will likely put you over budget.
