Well then!
Ok, the problem is that those fans aren't going to do a whole heck of a lot, except to keep your case air moving, which it probably is in the first place. In your case you have two paths to a better temp (wc aside):
1-duct the window fan to the cpu's HSF.
2-get a better HSF.
the $100 fan in the room isn't going to do anything but move air around. A WC setup could cost $200, and depending on your setup, could drop the CPU temp by 10 deg C, it's really hard to say for sure.