I guess I would say with a sub like the Outlaw, you'd probably be fine with the M60s. I have the M60s, and am curious to try the 80s someday...but I have a home theater set similar to yours in a room size similar to yours. Honestly, you could go either way. If you have the money, it could be fun to say..."I can go no higher!"
But the 60s are no slouch. I'm quite happy with them and can't imagine that I would need more.
But when I say that I'd like to try the 80s, this is coming from a guy who likes to "play". I plan on buying, moving around, adding another room set. So I don't mind doubling up speakers...I just move the other ones to another room.
If you have the money to say, ah what the heck, I'd say do the 80s. If not the 60s will pretty much get you where you'd want to go in any application.
Though I guess I haven't asked one of the critial questions, which is how far you'd be sitting from the front speakers...?
