My two cents:
#1 - Absolutely do not get Windows 7. Windows 8.1 64-bit is better in several ways, you can AVOID the new interface easily with Start8 for $5, and we are already seeing games optimized to run better on it (such as Battlefield 4).
It's likely we'll see future games work best on Windows 8 especially if Shared Tiles (streaming from System to Video RAM) become W8 exclusive.
There's no good reason to buy Windows 7.
#2 - PhysX card again? No. No. No.
It's a waste of money and can potentially make performance WORSE. Furthermore you need hacked drivers to even get it to work, and then it adds noise.
If you want GPU PhysX get an NVidia card such as the GTX780 or GTX780Ti and avoid AMD completely.
#3 - Motherboard: Not the best motherboard for quality (the MSI). I strongly recommend a compatible Asus board with good reviews.
#4 - DDR3:
I recommend 2x4GB if that's not what you have (not 1x8GB).
#5 - 2x Windows 7?? (Again, I recommend Windows 8.1, but why do you have two versions of W7 listed?)
#6 - HDD:
I agree with the Samsung 840, though you really should have a hard drive to do a backup Image of Windows (i.e. Acronis True Image and setup automatec, Incremental backups). Recommend the 3TB Seagate drive or similar.
Be advised that GAMES rarely benefit from an SSD aside from loading times so you could actually get by with a 120GB SSD and game from the hard drive. I've been TESTING many games on SSD and frankly it's really only a handful like Skyrim that benefit much (quicker jumping due to frequent location/building loading).
#7: G-Sync monitor (smooth gaming)
Since you are spending lots of money (some a little wasted IMO), you should investigate G-Sync. The short of it is I recommend you get a single GTX780 (i.e. EVGA 967Mhz ACX if available and reasonably priced) then buy the Asus G-Sync monitor with these specs once available (27", 2560x1440, 120Hz).
Here's more info:
https://www.youtube.com/watch?v=3PJjhBUSuHk
and
http://www.hardwarecanucks.com/forum/hardware-canucks-reviews/64586-week-nvidias-g-sync-monitor.html