Partial Upgrade and Silencing Questions

[superbike81]

Been reading over this site for the past few days, lots of info, pretty overwhelming at times with so many different components contributing to noise levels. I've learned quite a bit, but still need some guidance.

I normally build a complete new computer every 4-5 years, and do a partial refresh about halfway through that period, I'm at the refresh time now. I don't want this to be my usual refresh though, I never was concerned with noise or overall quality that much before, just wanted performance and nothing else. Now I would like to do something about the noise my system makes (which is A LOT right now) while I'm upgrading.

These are the items I'll probably be keeping (unless someone suggests replacement):

Asus AM2+ Motherboard (can't remember exact model, will update when I get home from work)
G.Skill 8GB DDR2 800 Ram (might upgrade depending on what my motherboard supports)
Corsair CMPSU-750TX Power Supply (is this a noisy power supply? Can't find much info.)
GeForce GTX280 1GB Video Card

I would like the computer to perform a little faster, but much quieter. It still functions very well for the few games that I play, and once Diablo III comes out, that will determine if I upgrade my video card early or not. Other than that, it works pretty well for what I do, which is mostly research and homework. I do leave the computer on for extended periods sometimes while downloading large files. I'm not looking for a major powerhouse, but I would like things to be a little more snappy, so here is what I'm thinking:

-AMD Phenom II 910T (already ordered, currently Phenom 9950)
-OCZ Vertex II 120GB SSD (already ordered)
-Western Digital Black 1.5TB for storage (already ordered)
-Smaller case, current is full tower no-name brand (I'm in Japan, shipping from Newegg is about $80-100 for any decent case so I'm limited to whatever is available at the computer shops locally. Will take a look at a few and post what I have available to me.)
-Quiet case fans for whatever case I end up getting
-Heatsink only CPU cooler (I don't overclock, so this should be ok right?)

Looking for any other suggestions to make things a little quieter and/or perform better. I've read about hard drive dampening and silicone fan mounts or something, but I'm a little confused by those. Fan controller maybe? Any suggestions for additions or substitutions I should make for my list? I would appreciate any and all advice.

Thanks!

[KyonCoraeL]

In my experience, the best way to make a considerable difference in noise is a fan controller. After getting The Scythe Kaze Master Ace fan controller, I could undervolt my fans down to an inaudible level when my system wasn't used for gaming. I could even turn off my fans during winter.