Cortmarshal

If your fan draws 160ma at 12v, that means it's a 75 ohm resistance. If you add a 50 ohm resistor in front of the fan, it'll give you 8v at the fan, and should only dissipate 1/2w, but keep in mind the resistor does get warm.
 
To be safe, I'd recommend you use two 1w resistors in parallel, meaning you need a rating of 100 ohms.

There are two versions of the HP Z400 motherboard. The first revision was a much smaller production run, but only had 4 DIMM slots. The 6 DIMM slots is a much more robust and reliable board. Make sure you update the BIOS as the latest HP BIOS for these 7 year old workstations, 3.60 Rev.A was released just Apr 14, 2016. It requires burning a CD to update.
 
The W3680 is the chip you want for LGA 1366, it's multiplier unlocked, cheap, and supported on the second revision board. There's NO overclocking at all to be had in the BIOS, just make sure enhanced turbo boost is enabled, and enhanced memory performance.
 
HOWEVER, software overclocking with the Intel Extreme Tuning Utility(and probably others) allows you to set the multiplier per core usage. i.e., if only 1 core is being used you should be able to get a  stable multiplier of 32x with good power supply on the HP board, which is a clock speed of 4.34 GHz I believe. The stock cooler in the HP Z400, supplied by Cooler Master, is quite good if you change the fan, though the proprietary 5 pin connector might require some plastic snipping to get a 4 pin fan hooked up to the top 4 pins. It'll probably then give you a low power cpu cooler error at boot unless you ground the first and last pins together somehow, just press F1. A minor inconvenience for the reduction in noise/ increase in cooling.

My mom's laptop has Windows 10 on an 80GB drive, and with 6GB of pictures, documents, and literally half a dozen other programs installed(VLC, Firefox, Chrome, Office, Minecraft), there's still 40.7GB of reported free space on the drive. I imagine the 32GB eMMC x86 laptops are running the same version of Windows as everyone else.

I've never tried it for gaming, but it feels accurate enough with fast desktop movements, whatever that means. Build quality is great from Logitech and it feels best with a more fingertip style grip.
 
The Energizer Ultimate Lithiums are 17g each, the Panasonic Eneloop Lite rechargeables are about 10-11g if you can find them in stock anywhere they'd be great.