Hey there, ImcLoud
Thanks for getting in touch.
First and foremost, let's start by getting better acquainted with your room!
You say your room is about 15' wide by about 20' long by 9' high. Is it enclosed? Or do you have openings to other rooms as well?
Also, how far away are you sitting? What's the basic sort of layout of your room. Do you have your TV mounted or positioned on a TV stand right against that 15' wall? Do you have your couch out into the room about 12 feet away from the TV, or do you have the couch pushed all the way back against the back wall so that your distance from the seat to the TV is closer to the full 20' length of the room?
We need to know the basics of your room before we can make suggestions that best fit your needs
Even if your room is enclosed, it's would still be 2700 cubic feet in air volume, which is a medium sized room. The HSU STF-2 subwoofer that I've recommended in this package will perform alright in a room that size. But if the room has openings to other parts of the house, the STF-2 might start to struggle a little bit, and you will want to consider a larger, more powerful (and more expensive) subwoofer.
The room really determines everything. And you do NOT want to skimp on the subwoofer! You would be far better off to use your $1000 budget to just buy one pair of good front speakers and a subwoofer that can properly handle your room size vs. getting all five speakers and a subwoofer that is not capable of handling your room size right away! But it all depends on your room and seating distance. So we've got to start with that first
There are lots of options for speakers. As others have pointed out, you always want to get a really good match across your front 3 speakers. This is a particular gripe of mine when a sound pans across the front soundstage, and the timbre of the sound clearly changes as the sound goes from Left to Center to Right, or vice versa. I want that sound to have the exact same timbre as it moves across the front 3 speakers - which is the way it SHOULD sound.
From what you've said so far, you seem to be concerned with being able to get high output (loud), and it also seems like maybe you have limited space for your center speaker, perhaps? I'm not sure. I'm just guessing based on what you've said. Again, we need to know all about your room.
So what is your room's layout? Does it have openings to other parts of the house? How far away are you sitting? How is the TV mounted or what sort of stand do you have the TV on? And just in general, how do you have the furniture arranged?
We'll get you sorted out as soon as we have a better picture of your room