Well it looks like you have a pretty good setup there. I would recomend a top exaust fan, (go large and quiet, 120mm or so) and maybe a side fan to help with the video card cooling and fresh air to the cpu.
First thing to look at is how much area the vent holes in your front cover provide. A lot of older or cheaper cases have 3-4 fans and no damn holes in the front to let air in. Exhaust fans will do you no good if they start pulling a vacuum because of inadequate venitlaiton openings in the front.
Best case mod for under $0.50 canadian. Take a file or dremel tool and open up the holes in the front of your case so the open area is 50% bigger than the open area of your intake fan.
Option 2 (not as good because it messes up the way the airflow diagrams in the above posts show works best) pop open any unused drive bay covers and if that drops temps cut slots or drill lotsa holes in the covers and put them back on. Note I have had no luck using the drive bay fans that blow air in fromt he front. I think they just end up blowing hot exhaust air off the HD's onto the cpu.
Manufacturers avoid the needed front air holes because it lets out the noise most users complain about. The cases are getting better though. Manufacturers are opening up much more front vent area and using serpentine arrangements to trap sound while letting air through.
what do you mean by that?
i have to 80mm fans on the side of my case
both blowing into the case
one on the cpu
and one over the pci and agp
is that good?
or r you saying to have it one blowing on the cpu and one blowing out of the case over the pci or agp