The m22's will do a good job for both HT and music as a rear channel. I think they will do a little better on the music side of things, but are great for both. If your room was shorter I would say a Qs8 might do a little better as it has a tweeter firing left and right. Either way, you will have to figure out how to mount them near the back of the room..

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85