Was going to suggest the M1's as rears when you suggested the 686's were too deep!!
Your on the right track when you suggest the KEF and B&W style packages, but I find my QA set up sounds much better than my friends KEF 2005.2 speaker package, when it comes to music.
As for Pioneer........I just think the receiver look very 'blocky' and unattractive, and I bet the gloss finish will attract so much dust to stick to it! Saying that, I do realise some of them sound superb, but I'll stick with my Denon AVR2310 anyday!
I would seriously consider the B&W 685 package, with M1's really.......small surrounds, and stand mounted fronts...just what you are after? I would suggest buying it all separately and going for the B&W 610 sub too........
The two QA speaker packages will be be as good as the B&W combination, I imagine.....