This is my first build and i have made two list of computers that i would build. Which one would you pick or change, i need your Opinion!!!!
 
Intel Core 2 Quad Q9450  
EVGA 132-CK-NF78-A1 LGA 775 NVIDIA nForce 780i
EVGA 01G-P3-N897-AR GeForce 9800 GX2 SSC 1GB  
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066
OCZ GameXStream OCZ1010GXSSLI ATX12V / EPS12V 1010W Power Supply
Thermaltake Armor Series VA8000BWS
Seagate Barracuda ES.2 ST3250310NS 250GB 7200 RPM
LITE-ON 20X DVD±R DVD Burner with LightScribe
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Intel Core 2 Quad Q9450  
EVGA 132-CK-NF78-A1 LGA 775 NVIDIA nForce 780i
EVGA 512-P3-N862-AR GeForce 9600GT Superclocked 512MB 256-bit
                Then sLi an 9900Gx2 When it comes out
G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066
OCZ GameXStream OCZ1010GXSSLI ATX12V / EPS12V 1010W Power Supply
Thermaltake Armor Series VA8000BWS
Seagate Barracuda ES.2 ST3250310NS 250GB 7200 RPM
LITE-ON 20X DVD±R DVD Burner with LightScribe
 
 
Also should i be thinking of getting liquid cooling?
This rig should last me 2+ years

I would choose the first option.
 
SLI isn't really worth it in my opinion unless you are using at least an almost top of the line GPU. I don't consider a 9600GT near top of the line.
 
A 1010w PSU is way, way overkill unless you are think about Quad SLI. A PC Power & Cooling 750w PSU will be more than enough with room to spare.

 
 
Should i upgrade the motherboard to eVGA nForce 790i Ultra and get 4gb of ddr3

Slow down! What are the uses of this pc? Any overclocking? How long do you plan to keep it?

 
Gaming, media, internet surfing, etc. I would like to keep it 2+ years.

I'd get a GA-EX38-DS4 and a Silencer 610W or 750W and forget SLI. A single 9800GX2 is plenty.
 
Get a Q6700 (it's only $300 these days) and overclock to 4 GHz.  
 
Forget DDR3 too, it's not that much better than DDr2 and it costs a lot more.

So no overclocking? No need for liquid. The stock coola is alright.

Def. dump the nvidia mobo as you're not taking advantage of SLI right away. By the time you want to add a 2nd card, a similiarily priced more powerful card will be out. X38 would be the minimum for 2+ years. Another good board is ASUS P5E.