Need some help choosing hardware

[Sosero]

Okay.. So basically I'm planning on upgrading my computer with "some" new hardware. I don't know whether I'm going to get myself a Core 2 Duo or a X2 though (plus memory and MB along with that), and that's basically what I need help with. This is what I was thinking about:

PSU:
Probably getting Tagan Easycon 530W or 580W

GPU:
Geforce 7900GT 256MB
or
ATI x1900xt 512MB

HD:
Seagate Barracuda 7200.10 Sata-300 320GB

Option 1:
Athlon64 X2 4200+ s939
1024 DDR400 (2x512)
Some MB

Option 2:
Core 2 Duo E6300/6400 (depends a bit on price)
2048 DDR2 533/677/800 (2x1024)
Some motherboard (haven't looked into this that much)

Now.. the reason I only put 1 GB memory in option one is that I already have a 1 GB of it (mostly cheap sticks though), so I might be able to put some more money into a GPU if I go for that option.
No matter which option I go for I could use some assistance in choosing memory (manufacturer, latency etc) because I really don't have any clue of how that works. My wallet will most likely be a bit limited if it comes to getting DDR2 so prices/performance will be rather important there, if too much money have to be spent to get decent performance it's not really an option for me

 

[clawlan]

go e6300 and overclock if familiar with it. if not, go e6400. outdoes most the x2's.

 

[Sosero]

What kind of memory does conroes want then? There's three types supported and different price-classes in each type.

 

[Bobthelost]

Conroes like DDR2, there's quite a few reviews of which exactly you should be looking at on the main site, take a look but the short version is cheap 667 and forget the latencies.

If you want to save money then go for the 7900GT and get a 400W or 430W PSU, or the X1900XT and a 450W PSU. Normal suspects on brands, seasonic, fortron, enermax, etc. etc.