Hi Matt, Welcome.
You should look at Nick's build thread and peruse some of the other threads.
It sounds like you've already done a fair amount of analysis. I'd offer up only a couple observations.
First, I wouldn't let the impedance of the M80/VP180 dissuade you. Those are Axiom's "ultimate" HT speakers and that is a pretty big room. If you can swing the extra money and extra space, well, you know. You can always add amplification later if you find that your receiver doesn't power them as loudly as you'd like, but I very seriously doubt that happening.
That being said, I think you'll love the VP160/M60 combination and it's probably more than plenty.
Second, I'm glad to see you're planning for a second sub. Again, that's a big room. I'd also wire for multiple possible sub locations. I'd really recommend two subs, and maybe the VTF-3 or similar. You can spend an ungodly amount of money on subs. Hsu presents a good value, as does SVS and many other companies including Axiom. I really think - in view of your overall plan and room size - you're a little undercapitalized on subwoofer capacity for movies.
Because the QS8's are so good, I didn't get a cost-proportionate thrill going from 5.1 to 7.1 in my room.
Get plenty of electrical circuits in there.
HAVE FUN!
Sub locations are covered, there is 4 outlets wired in the room for RG6 (RCA) and 12/4 wiring. Each outlet in located near the room corners in the front, and near the seating area. There is also AC outlets near each sub outlet as well as around the room.
The seating is Lane home theater power seating set of 4 in a row with a butt kicker mounted in each chair (it is wired for RG6 (RCA) and 12/4 feed to each chair in-floor).
Budget wise, I could go 2 or more subs from the start. The budget is not really an issue (other than the wife budget and what she thinks it should costs, which is a whole different subject). I am unsure if I need two subs with the kickers and in cabinets speakers. I would rather grow the system then give away gear to my son-in-law as I've done in the past.
