Thanks for all the tips everyone. I was originally planning on just going with what I have in my living room, the Epic 60 system with an additional pair of QS8's. I thought about going atmos, but there is no wall under that I-Beam. It is one big room, so I have nothing to mount all those side speakers too. I can only mount them directly to the ceiling or surface of the I-Beam. I considered putting up a wall and separating the two rooms, but it would make everything just look waaaay to small.

I am not a huge audiophile, I just want it to sound good without going too crazy. I really don't plan on doing any acoustical treatments, besides the drop ceiling and a few area rugs.

Here are a few more pictures so you can get an idea of the space. One is a quick drawing in SketchUp I did. The first four photos are from each corner of the room and the last two are the front and rear wall of the theater portion of the room.