Welcome to the forum!
I have recently heard the M2's and am the proud owner of M22Ti's and IMO you could easily get by with the M2's even 3 across the front if you can fit one above or below the TV. The Vp100 is also an admirable choice. I have one as well(also a Ti) and it has been very good to me over the years. If you plan on listening to music then the little better lower end of the M22 would be beneficial other than that difference the M2 is great bang for the buck.
I would get the STF2, you can never have too much subwoofer, but you certainly can have too little
You are in control of the output but you can't get more out of one that is too small.
Get the 508, that is a very good deal.
