Hey, thought I'd pop back in with my progress, this is what I have done:
What I bought:
Can of Compressed Air
Antistatic Wrist Strap
Arctic Cooling MX-4 Thermal Paste
Arctic Silver ArctiClean
Cooler Master Hyper 212 EVO CPU cooler
Zalman Z11 Plus case
The Zalman Z11 Plus is amazing for the price, it has so many features and came with 5 fans already installed, 2 of them are dedicated to the hard drives though.
What I did:
I carefully took my computer apart and blasted each component with compressed air to clean off any dust.
When it came to take the motherboard out I placed it down on a flat bench and carefully removed the northbridge heatsink, using a little thermal paste remover on a lint free cloth I wiped the northbridge chip and heatsink until shiny. Applied a little drop of MX-4 Thermal Paste and carefully secured the heatsink. (forgot to use the purifier...)
Then I finished off installing everything into my new case, then focussed on the CPU, removed the stock heatsink, brackets and backplate and secured the new backplate.
I used a couple of drops of thermal paste remover and cleaned the CPU, then a couple of drops of surface purifier until it was nice and shiny. I used the Pea method for the MX-4 Thermal Paste, put a pea sized drop in the middle of the CPU and carefully lowered the Hyper 212 EVO heatsink onto the CPU and gave it a little wiggle, then secured it, attached the fan and finished off the installation.
I now have 4 120mm fans in my case, front and bottom intake, back and top exhaust with two smaller fans built into each door which I believe are exhausts for Hard Drive heat, you can see that design by looking at the case.
I didn't get around to doing a fresh install of Windows 7, but after doing all of that my system seems pretty stable, I can game for as long as I want without crashing, and I did a Prime95 small FFT test and the max temperature of my CPU was 40*C using 93W of power and the fan was only around 850 - 890 RPM, it can go to 1600 RPM if needed... so that's promising.
In HWiNFO64 while running a small FFT test, I'm not sure what these refer to but, Temp 1: 32*C, Temp 2: 48*C, Temp 3: 52*C.
I did a FurMark test and stressed my GPU, the temperature went as high as 73*C and was steady at that temperature for about 20 minutes before I closed and called it a success I guess.
Things still of concern:
Even after putting everything into my new case, I touched the northbridge heatsink and actually burnt the end of my finger after touching it for about 4 seconds... not sure if that's bad. :/
When I tried a large FFT test and torture test, although the temperatures were all very similar to when I was running a small FFT test, after a couple of minutes or so my system does crash, just completely stops responding and requires a forced restart.
Not sure what that really means... but everything else runs flawlessly, no game or video or anything else has created a problem. I was just using the preset tests in Prime95, nothing custom.