Now that I know how to properly use SpeedFan, I've played around with the temps a bit and I figured out why the fans would always creep back up to 100% even under practically no load - I had set the Desired temps too low. I have an i7 2600 in a Silverstone GD05B with a Galaxy 560 Ti, etc. This case is small, so there's not a whole lot of air flow. What I figured out is that I really can't get my CPU temps below 38*C, even with all of the fans at 100%, but my Desired temps set in SpeedFan were set to 32*C so the fans were working up to 100% without ever actually getting to that Desired temp. Now I have my Desired temp set to 45*C and not only are the fans running at super low speeds but my temps are still 38-43*C. It would be nice to have a lower ambient temp but I won't complain since it's not overheating and I can't even hear my PC anymore.
Speedfan is a b**** but OK if there's no other way with your particular board. But the first think I'd look at is the BIOS settings for fan control. the second thing I'd take for a cruise is the bundled motherboard software.
someone already said "Fan Xpert" is useless, but it isn't useless. On ASUS boards, it is just unnecessary unless you choose to use it so you can adjust fan curves in Windows without restarting and entering the BIOS directly. My ASUS board has 2 PWM CPU_FAN ports, 1 "Pump" port, 6 Chassis-fan PWM ports 2 "assistant" fan ports, and a few others. All the PWM ports can also accommodate 3-pin fans and configure as either PWM or voltage-control for each and every one. The software for Windows is "ASUS Suite 3," but custom-tailored to my Sabertooth Z170 S. The fan-control component is named "Thermal Radar"->"Fan control." This is really bloatware if you don't use the other features, but I don't run it at startup since the changes it makes affects the BIOS settings and -- once configured-- don't need the software. I just haven't bother to uninstall it yet, and it has an active process that grabs ~3% of the clock cycles even when the software isn't running in the system tray.
If you can't get decent fan control that way, your next possibility is likely SpeedFan, because it's been around for a long time and additions of additional sensors for motherboard and CPU are part of the developer's routine. It is likely the update additions for SpeedFan lag behind current gen motherboards to some degree, because I'd think that would be a daunting job.
And -- it's a b**** to configure, but I said that.
If you lack sufficient motherboard fan headers -- PWM or 3-pin -- to execute your plan, then the step after that involves examining some splitters like the 8-port Swiftech ($12 or so), wiring 3-pin fans in parallel or purchasing a splitter or bus for them.
And the last resort -- a 3rd party front-panel/bay or circuit-board controller with onboard processor and USB-to-motherboard connection and software, like the Aquaero models.
At least if you follow that sequence of priority, you'll avoid spending more than you need to.