Building New Rig - Need Feedback

K I've been out of the loop for awhile but here is the short story. I'm looking to buy a new rig for around $1,000 or less. I'm looking for feedback on what I want to get. I'm not a "hard core" gamer or anything, but I love to run things at high res and very smooth. The nuts and bolts are the following.

1) AMD Athlon 64 X2 6000+ (what is this when compared to a pentium in gb and is a 6400+ worth the extra money?)
2) 500 Watt Power Supply (Could I just stick with less if I wanted? like a standard 450?)
3) Asus M2N-SLI Deluxe nForce 570 DDR2/800 w/ Dual PCI Express (Is a 590 worth it, is SLI the way to go nowadays?)
4) 2 gigs of ram (could I update to 4 with ease b/c I have two other gigs from an old computer? Is 2 enough?)
5) Nvidia GeForce 8600 GTS 256 MB EVGA Superclocked (is a 512MB worth it? Is this a good card? Do you have to run 2 video cards with an SLI based motherboard? Don't laugh I seriously do not know. Oh, and what is the difference between a GT, GTS, etc.) *Update -Been told an lesser expensive 8800 will be released very soon so going with that*
6) 320 GB Hard drive 16MB Cache (what's the difference between 8 and 16 in cache...speed? Will 8 be fine?)
7) Windows Vista Home Premium (What the heck is the difference between 32 and 64 bit versions?)

I certainly appreciate you taking the time to read this and any feedback on this stuff would be appreciated. I'm open to change any and everything.Thanks!!

K I've been out of the loop for awhile but here is the short story. I'm looking to buy a new rig for around $1,000 or less. I'm looking for feedback on what I want to get. I'm not a "hard core" gamer or anything, but I love to run things at high res and very smooth. The nuts and bolts are the following.

1) AMD Athlon 64 X2 6000+ (what is this when compared to a pentium in gb and is a 6400+ worth the extra money?)
2) 500 Watt Power Supply (Could I just stick with less if I wanted? like a standard 450?)
3) Asus M2N-SLI Deluxe nForce 570 DDR2/800 w/ Dual PCI Express (Is a 590 worth it, is SLI the way to go nowadays?)
4) 2 gigs of ram (could I update to 4 with ease b/c I have two other gigs from an old computer? Is 2 enough?)
5) Nvidia GeForce 8600 GTS 256 MB EVGA Superclocked (is a 512MB worth it? Is this a good card? Do you have to run 2 video cards with an SLI based motherboard? Don't laugh I seriously do not know. Oh, and what is the difference between a GT, GTS, etc.)
6) 320 GB Hard drive 16MB Cache (what's the difference between 8 and 16 in cache...speed? Will 8 be fine?)
7) Windows Vista Home Premium (What the heck is the difference between 32 and 64 bit versions?)

I certainly appreciate you taking the time to read this and any feedback on this stuff would be appreciated. I'm open to change any and everything.Thanks!!

jim8015

The X2 6000+ you should be fine with. Your Power Supply looks fine as does the rest of the specs.

For an SLI motherboard you don't need two graphics cards, they work with just one card too.

As far as your hard-drive, there is no noticable difference between the 16MB and 8MB caches so go for the cheapest.