It is against the laws of physic that adding more of anything to a playback system will get you anywhere closer to the original.
I have a 2-channel 2-component music only system that so happens to also play moves via the OPPO BDP-105D and I also use the OPPO's passive volume attenuator.
You have a budget of X dollars for your desired multi-channel config. How is spreading that budget more thinly across 7.1 channels (or whatever) going to help you when that same budget could go toward improving your 2-channel system?
Also, with multi-channel you have far more cabling and speakers, more chassis', and more power supplies.
Most important is that more power supplies imply more noisy AC coming in from the street that must be properly dealt with e.g. proper line conditioning, power cables, etc. and each power supply also induces mechanical vibrations into each chassis that also much be properly dealt with.
Moreover, the more chassis' you have the more mechanical vibrations are captured within each via air-borne and internally generated and again, much be properly dealt with.
And then there's the aesthetics. Fewer amps, receivers, cables, speakers, etc. all translate to an improved, more professional and simple installation with far less clutter.
I'd like to suggest going the other way, focus on creating a vastly superior 2-ch system that excels at music and just so happens to excel at movies as a by-product. If you focus on the simple, you can still acquire a sound no multi-channel system can touch. Only you won't be hearing any star fighters flying over your shoulder.
I've included a few pics. Now my decor may not impress you but it's all about performance for me. Which can only come from simplicity.
BTW, the OPPO is a fabulous performance for both music and video and is vastly superior to the $9k Esoteric unit I owned previously.
