Given that you want to avoid upgradeitis (always a wise decision
) I would go with 3b :
2 x M60 = $1120 CAD
2 x QS8 = $620 CAD
SUB SVS PB10 = $600 CAD
Hang the QS8s on the wall for now, buy stands and center later.
TOTAL = $2340 CAD, 2670 if you can't hang on the walls.
Here's my thinking :
- no matter how good the bass on mains is, a good sub makes a HUGE difference in movie enjoyment
- in a 15x15 room you are not going to have a huge seating area so you can probably live without the "anchoring" effect of a center channel for a while
- you are totally future-proofed if/when you get a larger room in the future (that's the main downside with a smaller system, by the way)
- you have great floorstanding mains for stereo music
- you have QS8s
I am running the FMS-QS stands with QS8s and am very happy with them, but if I had side walls in my listening room I would be hanging 'em on the wall instead. You can hang QS surrounds pretty much anywhere (mine weren't even at the same height) and they still work well.
EDIT -- two other points :
1. Remember that you get a 5% discount off the price when you buy any 5 speakers, or in fact any 5 "things". If you go with option 3b that is only 4 "things" so buy a cable or something to get up to 5.
2. Bigger speakers are not automatically better, although they are generally "better in a bigger room". In a small room M2s or M22s with a good sub will be as good as you would ever want, but in a much larger room the little speakers will sound great at low volumes but they won't be able to open up and fill the room at high volumes.
I ran M2s plus a big-ass sub for a while in a 10x13 corner of a larger room and was very happy with the results. The M2s are extremely accurate speakers, even compared to the rest of the Axiom line, but they are small. When I used the whole 13x23 room the M2s sounded "small and weak" unless I sat close while the M60s sounded "big and clear".
If you are not likely to move into a bigger room in the future I wouldn't worry about future-proofing so much -- but if you really want the M60s and don't mind adding the last bits later then you would always regret getting anything else.
I started with M2s and a sub, then added M60s about 9 months later, then a center, then QS8s, then finally QS stands, spread over about 2 years.