Like bathroom exhaust fans, there are likely quieter, more efficient 80mm cpu fans than the Arctic or the one's Acer uses. Perhaps a google search is in order.

Yeah, there's not too much that can be done with fan design other than changing the pitch of the blades. Steeper pitch moves more air at the same RPM, but moving more air makes more noise. So, the quiet fans move less air at the same fan speed, which means there is less cooling. The best solution for fan noise under a heavy load is a more efficient heat sink, so more cooling happens with the same air flow. That's typically one that's taller or more fins in the same area. Taller has problems with some cases, more fins in the same area gathers dust faster so clogs more often.