I'm thinking of getting a pair of M60s and a VP-150 as my fronts in my HT.

I know that surrounds don't have to match perfectly for movies where they're generally used for SFX, but i think it's a lot more important for gaming where it's virtually "recorded" in multi-channel. So I was wondering if getting four M2s as my surrounds will suffice in a 16' w x 17' l (opens into kitchen at back, hallway at mid-back side) x 8h room. Not just for a sweet spot, but in general.

My reason for leaning towards the M2s is:

1) I don't think the QS4s or QS8s are suited for the room, as the places where i'd ideally mount them are basically open spaces or a window. I can probably stand-mount some bookshelves somewhere or another.
2) They're nice and cheap, which is good because the M60s aren't so much.

On that note my final question is

1) Will the M2s have a change in timbre from the M60s?
How about the M3s? I definitely want all 4 surrounds to be the same, and if I can get a good timbre match with the fronts it's something i would prefer. I really don't want to buy 4 M22s just to use as surrounds, at least not right now, financially speaking.

And with all of the above said... how about the M50s as my fronts instead? The 60s really do seem to be worth it but again I do want fairly timbre matched all-7-speakers.

The M2s are going to be closer to the M60s than the M3s are. Likewise, the M3s will be closer to the M50s.

My room also opens to the kitchen in back and the hallway midback, and the Qs work just fine, so if you can work them in, I'd recommend them.

I have a pair of M50tis (2 generations back) and frankly, they can't hold a candle to my M80v2s, nor to M3v2s that I have compared to them. I've heard M60v2s, but not in a direct comparison to the M50s, but I still think the M60s are a big step up. That said, it's possible that the M50v3s are also a big improvement over what I have.

I have both M60s and M2s, and find their timbre to be very similar. At higher volumes you can definitely tell the difference, but at lower volumes with a subwoofer the two are surprisingly hard to tell apart. I also used the M2s as surrounds for a while (after getting the M60s but before getting QS8s) and found they worked very well, however the QS8s definitely gave a more "spacious" feel.

If the surrounds have to go near your listening position (a few feet) you might want to think about getting 2 QS8s rather than 4 M2s, unless gaming makes more use of 7.1 than movies do.

If you are looking for timbre matching I would either go with M60/M2 or M50/M3 rather than mixing M60/M3 or M50/M2.

GEV, welcome. For timbre matching across the front, consider the M60 mains and a vertical M2 center. The QSs definitely impart more spaciousness to surround sound, but if this isn't what you want for your application, again the M2s are a good match for the M60s above the bass area.