Crewing Vega speakers are absolute power pigs. They consume amplifiers and get louder but rarely distort. The Onkyo not up to the task. Without getting too crazy, would look at Outlaw as their power regulation is more solid than Onkyo. Not sure how many channels they do today.
Don’t get me wrong, Onkyo in past has done well with 2-channel, just not theater surround stuff.