PSU & RAM: $145- Corsair TX750 & Corsair Vengeance 8GB(8GB is more than enough for gaming needs, also this PSU can allow you to add another 670 in the future)
8GB is plenty and that PSU should allow for a second 670 down the road but I'm not sure.
SSD & Motherboard: $244- Crucial M4 128 GB & Asrock Z77 Extreme4(Fast SSD, with Reliable motherboard that supports SLI/Crossfire)
Personally I'd go for a large 500GB - 1TB mechanical drive over an SSD as that room will run out quickly depending on what features you run. As far as that motherboard goes - I had it and it's not the greatest, it shorted out quickly every time I started it up and I eventually e-mailed Asrock about the problem with no luck. I finally returned it back to Newegg and got this: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
This is a gaming system and that will be its only use. i don't know much about operating systems and need help finding out what one would be the best for my build.
Windows 7 Home Premium - <=16GB RAM, basic Windows functions, card games, Windows Media Player, HTPC functionality, DVR functionality
Windows 7 Pro - >=16GB RAM, also has backward compatibility for XP legacy programs and drivers, remote desktop
Windows 7 Ultimate - all features of 7 Pro and Home Premium, extra security functions, XP Emulation mode, language packs
Disagree with g-unit about the HDD. I'd nuke it completely and trade up your SSD to 256GB. I have a 160GB SSD and will not fill it up before its useful life is over.
Also, I have the Extreme4 mobo and love it. Unless something goes very wrong in the coming months/years I'm done with the other manufacturers.
I guess I'm used to using my PC for way more than just games - I have a rather extensive media collection that I store on the 1TB on my computer (although it's only 1/2 full). I'm personally not a fan of running SSDs above 128GB due to the ridiculous cost per GB of the higher capacity drives - that's where the 1TB comes in handy.
I'm kind of iffy on Asrock right now - I had originally purchased the Extreme 4 for my system and it kept shorting out and giving me boot loop issues - I contacted Asrock immediately about the problem - it's been two weeks and I have yet to hear back from them.