Please help me out on this destop build

[hellohowru]

I am a newbie in computers but I want to build a computer myself
please let me know if there is any problem with this build
I would like the computer to last at least 4 years thanks
this would be a gaming system for my brother to play all the new games

CPU: AMD Athlon 64 X2 4200+ Dual Core Socket AM2

Memory: OCZ DDR2 PC2-5400 667MHz EL Gold Edition 2GB (2X1024MB) Dual Channel Kit

Motherboard:
I don't know which one is better, please let me know
also I don't know if I shoud get SLI please tell me the difference between SLI and non SLI
Asus M2N-SLI Deluxe Socket AM2
or
MSI K9N SLI Platinum Socket AM2

My other 2 choices for non SLI are
MSI K9N Platinum Socket AM2
or
Asus M2N-E Socket AM2

Harddrive: Seagate Barracuda 7200.10 250GB SATA NCQ 3.0Gb/s 16MB Cache

Video Card:
I don't know how to decide either please help me out
MSI NX7600GT-VT2D256E GeForce 7600GT(560MHz) 256MB DDR3(1.4GHz) 128-Bit Dual DVI Tv-Out SLI Ready PCI Express Graphics Card
or
Asus EN7600GT Silent/2DHT/256M nVidia GeForce 7600GT(560MHz) 256MB GDDR3(1.4GHz) 128-Bit DVI-I HDTV-Out Passive Cooling Heatsink SilentCool 2 PCI Express Graphics Card
or
Asus EN7600GT/2DHT nVidia GeForce 7600GT(560MHz) 256MB GDDR3(1.4GHz) 128-Bit DVI-I HDTV-Out PCI Express Graphics Card
or
any other good suggestion around the same price

CD/DVD-ROM: Samsung SH-S162L LightScribe 16X Beige DVD Writer

I know you are all experts in computers please give me a little help on my new destop for my brother, give me some comment on this build cause I seriosuly don't know which motherboard and video card are better
also does OCZ memory fit those motherboard?
please please please give me some suggestion
thanks

 

[ceewi1]

What's your budget?

please tell me the difference between SLI and non SLI

SLI lets you use two nVidia cards to improve performance. Here's a bit more info: http://www.slizone.com/page/slizone_learn.html

Not really worth it, IMO.

I don't know how to decide either please help me out

They're quite expensive for 7600GTs, look at the cheaper eVGA option:http://www.newegg.com/Product/Product.asp?Item=N82E16814130017

Better yet, get a far superior X1800XT at a similar price to the cards you're looking at: http://www.newegg.com/Product/Product.asp?Item=N82E16814102007

also does OCZ memory fit those motherboard?

Yes

 

[hellohowru]

my budget would be around 1200 CAD for the destop
for evga is eVGA 256-P2-N553-AX Geforce 7600GT CO 256MB GDDR3 PCI Express x16 Video Card a good card to have?
also for the non sli board
i would like to know the MSI is better or the ASUS is better?
btw thanks for giving me the suggestion

 

[hellohowru]

also what kind of power supply should i put into this system?
do i need a lot of fan?
do i need to add a cpu fan to this destop?
also what PSU should i use for this system
thanks