I think that 7 fans is way too many.
Overclocking is a hobby, but to me part of the hobby is to be able to do it cheaply and quietly.
Fans is a necessary evil.
I have a case that can have 7 fans (two in front, two on the side, two at the rear, one on the top) + 2 fans in the power supply. Initially I though about putting lots of silent fans. Now I think this would have been too loud.
I got high flow 92mm Panaflow fan (on CPU heat sink) and it is acting on my nerves, way too loud for me. My CPU temps in low 30C idle. Now I am investigating a best way to lower this fan noise. I do not mind CPU getting well into 60C range (under load), if I can have less noise.
Even when I put 1.95V Core I still have more then enough cooling with just 3 case fans. After some testing I realized that current ATX system, have been designed to push air out, so negative pressure is great for it.
I always have one fan on the side to pull cool, outside air right into CPU cooler fan.
Fan on the top of the case is useless, since I do not have any heat critical component (just couple of DVD drives, which seems to cool themselves passively just fine) up there.
Putting front intake fan did not do much good ether. Maybe HD stayed a bit cooler, but CPU temps did not change.
What does make a LOT of difference is to have two exhaust fans at the rear. With one rear fan I get 40C+ CPU and with two I get 30C+.
I can't tell you the difference between different fans that you bought (I still have to return few of mine to Fry?s), but you do not have to have a lot of fans to have a cool running system.
I had a friend who's PC did not worked too well on hot days, so he took off the side and pointed big fan (from Home Depot, something like 2 feet in diameter) into it. Worked very well. I think this setup was much quieter then with Tornado. Esthetically not very nice though.