if you're looking to minimize electricity use/noise, then take out fans until the case temp starts to rise. you can take out that PCI exhaust thing, they dont' do anything. this is what i have:
2 intake 80mm
2 exhaust 80mm
FOP38(delta 34cfm fan)
small 486 fan for my MX's heatsink
i don't really need all of those, i just like hearing them 😛