Upgrading my computer - NEED ANSWERS QUICK FOR BOXING DAY

[invisible_wall]

So I'm finally upgrading my computer and wondering about a couple of things. This is a budget gaming comp.

Current Specs:
Operating System: Windows 7 64-bit
Processor: Intel Q6600 @ 2.40GHz
Memory: OCZ Platinum PC2-6400 DDR2-800 2GB RAM
Graphics Card: GeForce 8800 GT
Power Supply: Corsair 520W
HDD: Western Digital Caviar 640gb SATA2 7200RPM


1. I'm thinking about getting more ram. Would there be a noticeble difference between getting 2gb more or 4gb more?

2. Any new RAM I get would be compatible as long as it's also @ PC2-6400 DDR2-800 right?

3. Would getting another 1TB internal HDD for storage use a lot more power? Is 520W enough?

4. Also considering getting a 24" monitor. Since the aspect ratio is 16:9, does that mean older games that don't support wide screen resolutions like 1920 x 1080 would look messed up if I tried to play them at resolutions like 1024x764?

 

[Fat.Clown]

1. I think more RAM would be good but, noticeable difference? it depends on what software you run

2. generally yes, but some RAM and mobo just don't play well together

3. HDD draws about 5 watts each

4. you can always set your video card to keep aspect ratio, that way games won't look skewed

 

[invisible_wall]

I have a Gigabyte EP35-DS3L. I assume that would work right well with most memory types. It's probably going to be Corsair 4GB XMS2-6400 DDR2. Would having 6gb vs 4gb be any different in games?