I'm looking at putting two M3's in my garage for stereo music streaming from my mac in the house. Right now I will source the tunes from an old ibook G4. In the future I will put in a tv and stream from appletv. At that point I would probably get a center but I doubt I would go further than that considering I already have two complete HT's setup in my house already . . .

I don't extra zones or fancy extras but need HDMI for sure. From what I've read, I'm leaning toward a AVR590 but wonder if I could get by with a lessor model??? I just want to be able to drive the speakers properly and not pay for more of a receiver than I need.