kidcool321, there's a few things you should know about your system before you build it. if you're making any rig over $1000, you should DEFINITELY have 2GB of ram. don't get that $100 per gig stuff, either. you said you're new to computers so i'm sure you won't be overclocking. that expensive stuff is meant for overclockers. amd would be a better cpu option for you but neglecting your gaming needs isn't good. don't worry about getting too much space and make sure everything is compatible. when making your rig, consider this list:
1. do i have 2gb of ram?
2. is my CPU compatible with my motherboard? (check to see if the motherboard takes DDR or DDR2 ram)
3. is my RAM compatible with my CPU? (check this by making sure it's DDR for AMD and DDR2 for Intel
4. for your case, many people are going to say your choice is horrible. don't listen to them. if your budget is $50-60 for the case, buy a $50-60 case. but get an aftermarket power supply. one that would fit your cause is the fortron 450w. it's $50.
5. do i have enough hard drive space? getting a 250GB drive is only $16 more than the 160GB you listed. if you do get the 250GB, western digital's SE16 drive is fast but samsung's drive is more reliable
6. does the video card fulfill my gaming needs?
7. and lastly, am i within budget?
you keep claiming how an AMD cpu is for you. with most games today, the computer is GPU-limited, meaning whether the CPU was overclocked to 5GHz or not, it really wouldn't make a difference because the GPU can't handle any more frames per second. you should most certainly get a powerful CPU, but not one so powerful you won't take advantage of it.
about the opteron 165 vs the X2 processors, opterons are dual-core processors (at least the opteron 165 and higher) and are made by AMD. they are basically A64 X2 processors built with server reliability. an opteron is not for you only because they cost a few bucks more per MHz since they overclock better, and you won't be overclocking. get the 3800X2; it's a good processor.
don't get a 7600GT. the X1900XT is probably too powerful for your needs but if you have the money, nothing wrong with spending it on it. i think a 7900GT or an X1800XT would be better for you (which ever one is cheaper). especially if you have a 19" monitor or smaller.
when you're searching for ram (assuming you're going the AMD route), search for DDR ram and get the CAS 2 ram that's under $140. it doesn't matter too much what the Cas Latency is but if they're all around the same price, might as well get the better stuff.
this Patriot ram is pretty good, especially for it's price (after rebate that is).
you had a question about OC and HSF. OC = overclock, HSF = heat sink fan. stock is what the CPU comes with it.
bamacre's rig looks pretty good. if you stick to AMD, up the CPU to the 3800X2. it costs about $50 more.
you can save about $15 by changing bamacre's case choice to the one you chose plus the fortron 450w power supply i recommended.
for a good AMD-compatible motherboard, the Epox 9npa+ Ultra is good for under $100.
if you go with my ram recommendation, you'll save another $18. you'll still be under $1200, but barely. what you could do, since you only play Counter Strike, is downgrade bamacre's GPU recommendation to a 7900GT or X1800XT. that'll save you a good $140. you'll be in the $1050 range after that. with shipping, etc. you should be at around $1100.
everyone here is here to help (unless you go to Off Topic
) so consider the recommendations and tips given. if you want to change some stuff, go right on ahead but try consulting us if you do.
enjoy your build, i'm sure you're going to have a great rig