In reply to:
it is my humble opinion that there is no such thing as "overkill."
I respectfully disagree with Jack on this one, because I have owned speakers that really sounded better in a large room than the small one they were in. I described it as them needing room to "open up".
My M60s are not like this, though. It was a big concern of mine before ordering (as I have a small 13' square room). Without question, my M60s, VP150 and QS8s "play nice" at lower volumes. I have no thoughts at all that they need a larger room, though I don't doubt they could fill a much larger room as well!
I think the EP500 sub is a good choice as well considering your kitchen is open to your living room. Even in my smaller room, I wish the 500 were available when I ordered my system so I could go a little deeper in the LFE than my 350 allows.
I think you're dead-on with your choices. Squeeze the trigger and post photos when you get them!