Is my Cooler Master Silent Pro M 850W good enough for my setup?

Yes, the 850 Watts PSU will be fine for SLI of any of the cards that you have listed. Here is some more information: http://www.bit-tech.net/hardware/2010/12/07/nvidia-gefo...

In case you are thinking of a 1,000 Watts PSU, here is a great one: http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Check the dimensions of this PSU. It is rather large.

One thing that caught my eye was the Intel stock cooler. This is adequate for normal use, but if you want to do any heavy gaming, multiple applications, then you should consider a good after-market heatsink. This is a great one at a very good price: http://www.newegg.com/Product/Product.aspx?Item=N82E168...

Yep! you'll have no problem powering any of the listed gpu's.
The CM Silent Pro M 850W is a quality unit.
http://www.hardwaresecrets.com/article/Cooler-Master-Si...
You could run into clearance issues with an aftermarket cpu cooler since all dimms are filled .
I can't find exact info regarding Sector 7 ram but i know Sector 5 ram is 43mm tall.
I agree with Ubrales though i think an aftermarket heatsink would be a good idea.
According to Noctua Viper II ram is shorter which is a good thing in your case.
http://www.noctua.at/main.php?show=compatibility_ram_ge...
base height and dimm intrusion are paramount when choosing a cooler for a dimm filled mobo.
Some cooler dimension info this applies to 1156 mobo but is easy to apply to a 1366
Just measure distance from middle of cpu socket to your first dimm
apply that measurement to width of cooler you're interested in.
http://www.tomshardware.com/reviews/lga-1156-heatsink,2...
Obviously cooler height is important too,is your case wide enough?

Thank you all for your replies.

I have the Original Antec Nine Hundred Case. I have a decent amount of clearance with the Stock Cooler which is surprisingly large for stock plus it have two speeds. I don't do Really Heavy Gaming. Occassional WOW at best at the moment.

According to Patriot Memory my memory is 44mm in height.

I don't want to invest in a PSU since I just got this one and it cost me nothing. I saved the money on it so i can a other components.

According to this you could run GTX580 in SLI on that PSU so your selection of cards is fine http://www.anandtech.com/show/4061/amds-radeon-hd-6970-...