Building a new computer, need some advice.

Hello everyone. I am new to the forms so once again hello. Anyway I want to build a computer for the first time but I need some veterans to check and see if things are compatible and will work well, feel free to make suggestions aswell.

Alright, well like I said this is my first time building a computer and I want a good one. I love to play games on my computer but my crappy old $1000 gateway is a while behind the times.

Here's the components that I want to use.

CPU - ]Intel Core 2 Quad Q9550
http://canadacomputers.com//index. [...] cid=CPU.84

RAM - Corsair XMS3 DHX 4GB
http://canadacomputers.com/index.p [...] AM.346.539

Case - NZXT Whisper Classic Series Full Steel Silent Tower Case
http://canadacomputers.com/index.p [...] cid=CS.220
Disk Drive - LG GH22NS30 Black SATA DVD-Writer
http://canadacomputers.com/index.p [...] cid=CR.184

Motherboard - EVGA 132-CK-NF79-A1 3-Way SLI Socket 775 nVidia
nForce 790i Ultra Chipset
http://canadacomputers.com//index. [...] cid=MB.157

Hard Drive - Western Digital Caviar Black
http://canadacomputers.com/index.p [...] HD.443.877

Power Supply - OCZ GameXStream 850W Power Supply
http://canadacomputers.com/index.p [...] cid=PS.808
CPU Cooler - OCZ Vendetta 2 CPU Cooler
http://canadacomputers.com/index.p [...] cid=FN.349

Thermal Grease - Arctic Silver 5 High-Density Polysynthetic Silver Thermal Compound
http://canadacomputers.com/index.p [...] cid=FN.687

Also I'm having trouble with a selecting a video card for my new computer. I want to go with a new card that will still be blazing fast in a few years. I want to be able to play my games with a max resolution of 1360x768 with all other settings maxed out to the extream. I will be playing CSS, Team Fortress 2, new EA Games RTS (Command & Conquer) and of course Crysis. I also want to be able to play games 3 years down the road without problems. I'm leaning towards the Nvidia 280 but I'm not quite sure. So someone please give me a hand with this. Please use the site in the links (Canadacomputers.com) for posting references, also I will not be able to SLI cards until a little later (Aftre Xmas at the earliest) as my bugdet is already maxed out.

Thanks for reading my increDdible long post, please go through it an tell me if everything is ok and will work. Also I heard about the 790i Ultra being very unstable is this true? Also will this case provide enough air flow.
Thanks again.

Thanks for everything

Yah its an HDTV that I use. Thanks, anyone know if the 790i Ultra Mobo is like as I want buying it but I've herd if its unstable, does anyone know if these issues are real and if they've been fixed?

Also, on that video card, you may be better with something good now but that's not overpriced, then put a better card in later as the system ages.