Another note along those lines is that one fan blowing into or out of the case moves x amount of air. 2 fans blowing in or 2 blowing out moves nearly 2x as much air (small losses based on what the air flows over to get into the case and such. However, one fan blowing in, and one blowing out, only moves something like 1.5x as much air. It was always better having all fans going in, or out, of whatever chamber you were working with. This is from our lab tests in HVAC class, and generally agreed on by the prof.

Some things I've done if it gives you any ideas:
1) I have a single 90mm fan at the very front of the hard drive cage, with three drives installed in the cage. This works for the Antec case and anything similar, may or may not for you. I also have three hard drives in it, so... cools them quite well.
2) I have only two case fans, both in back blowing out. They are the Panaflo L1-A's. There's L1, M1, H1, and U1, each flows progressively more air. (I also theorize the letters stand for low, med, high, and ultra but haven't seen anything to back that up). The L1-A's blow "a good amount" of air, enough to keep my happy that the case has a constant flow through it, but I can't quantify that amount. These fans are 100% silent. OK, 99% anyways. I can't hear them. (Also, my power supply blows air out as well, and there's slats in the front of the case where it all draws in from. Makes neat dust patterns).
3) On the CPU cooler, I have a Thermalright AX-7 heatsink. I think the bigger the better. More fin, more surface, more heat loss. Their SK-900 and some others are supposed to be even better. I have a YS-Tech adjustable speed fan as well. Some may consider it a pain, and I guess I wish it was in fact automated, but what I do is turn it down to nearly silent for surfing, and up if gaming. With the speakers up or headphones on I can't hear it anyways.
4) I don't have a fancy clear window on the side of my case, so I went ahead and grabbed a piece of fuzzy carpet remnant from a friend who just built a house. I put a small piece under the power supply near the CPU, and a large piece that completely covers the side of the case above the CPU. (I did wash it and brush it to get as much fuzz as possible off - yes it looked silly but satisfied me I wouldn't mess anything up with stray fibers). This little mod made a huge difference on the amount of noise coming out of the case.
5) Lastly, as an Athlon owner, I don't monitor temps too much, I just know they run hot. The difference between 40 or 50, even 60 if an hour into a high paced game, means nothing to me. So what if the CPU lasts 20 years instead of 25? I don't see it worth being concerned about.