I'm about to overhaul my system and would like to share it with you - maybe you have some recommendations.
My current setup is about 2 years old with some parts replaced 1 year ago.
Phenom 9850 BE Agena (stock speeds and cooler)
4 GB Apaces 667 DDR2 RAM
MSI n9800GTX+ OC 512MB
Asus M2NSLI Deluxe
Some Chieftec full tower case with 4 Zalman case fans
Velociraptor and 2 storage HDDs
Chieftec 550 W PSU
OC the CPU form 2,5 to 3 GHz, more if possible, equip it with a ZALMAN CNPS 9900
MoBo: ASUS M4N82 Deluxe
RAM: DDR2RAM 2x 2GB DDR2-1066 mushkin
Another MSI n9800GTX+ OC 512MB for SLI
Change case to SilverStone Raven RV01B-W
Did some calculations and the PSU should be able to handle the new build.
How does it look like? Have I missed any bottlenecks?
Neither the motherboard or RAM upgrades will give you any real performance boost and will cost you $200+....
I do not know if there is another reason for changing the case but, in the end, all it does is hold your parts. That is why I think it is wasted money
I would recommend that you stick with your current motherboard and RAM for now.
Get a new CPU cooler (good Best Hs List Here) and trying for your best possible overclock.
Add a second 9800GTX+ and pray your cheap PSU will be able to handle it.
If you want to play it safe, get a new Corsair, Seasonic, PCP&C or Antec Earthwatts 550w+ PSU.
Remember, not all PSUs are created equal...
With this lower cost option, you can save your remaining cash for a future i5/i7 or AM3 platform upgrade without losing the performance of your original upgrade plan.