Assumption: this is not going to be perfect. Every response saying it won't be perfect is obvious, but worse, such a response seems to say you don't have a better idea, but you're willing to tell cshepard that his idea won't work. The guys at this site are better than that.

A short sound bar won't match, as said. The Yamaha has its EQ system, which will help.

Phantom center channel is a GREAT solution unless people visiting you are speaker counters (that would be most of us!). They'll sense the center channel in the center.

Trust me, even though it doesn't sound reasonable, systems can have the speakers were way off perfect but the sound was not only great but seemed to emanate from the TV! In the middle of an install in my garage, I had only one speaker, four feet to the right of the display and three feet up, and I realized to my shock while watching a movie that the sound seemed to emanate from the middle of the screen... until I thought about it.