If your going to go with a vertical center, it would be better to get a matching bookshelf, like the M3 or M22, versus turning a center on end, which is designed to be horizontal.

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