Welcome to the board. Staying away from Bose is a wise move. The two problems that you are going to run into is on-walls generally don't have great sound quality. Second is there is no way that you will get room shaking bass in an 11,000cuft room with a single subwoofer. Especially within your budget.
So okay here are some ideas. If you must have wall hanging speakers I'd take a look at these discontinued
Energy Take FPS for $129 each for the left right and center. Just keep in mind that they are discontinued and finding an exact match for surrounds later on will be next to impossible. A exact match with the surrounds isn't critical but it's nice. You will need a sub with these.
A second option that would do a better job of filling that huge room would be a pair of Klipsch RB-61 bookshelf speakers for $500/pr. Klipsch are very efficient but aren't everyone's cup of tea. I'd try to give them a listen before buying or buy from someplace that takes returns. Start with a 2.1 system because that's all you can afford for now. Again you'll want a subwoofer.
The problem is that there is no $400 sub that is going to fill that room. You're going to be hard pressed to find a $1500 sub that will fill that room with room shaking bass. Another option would be just starting with tower speakers like Infinity's Primus P362 for $160-200ea depending on sales. The matching center is the PC350. Then wait on the subwoofer and surrounds until you have more money. The Infinities are really easy to drive.
Sources for subwoofers are Elemental Designs, Hsu Research, SVSounds. All are Internet direct and offer great quality and bang for the buck. And all three would be happy to help you size a sub (or two) for your room.