How large is the room? I tested some onwall m22's with my 350 and things sounded very good. The onwall 22's don't do as well in the lower frequencies as the regular 22's, but that won't matter as the 350 will pick up where they leave off.

My M22's are about 6-7 ft apart and sound great, I'm using a VP100 for the center upstairs and 350.

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