Do note that H97 and Z170 cannot run the same CPUs. The Z170 can run Skylake chips (i3, i5, i7-6xxx), but the H97 can only run Haswell chips (i3, i5, i7-4xxx) and that the Z170 needs DDR4 while H97 uses DDR3 (and H97 can't overclock but Z97 can). If you already chose a CPU and RAM, then you are locked into one of those two but if you are deciding whether to go Haswell or Skylake, I'd nudge you towards Skylake simply because it is newer.
That board has 5 fan headers, looks like there's no problem using 3 pin fans there. The Corsair AF140 Quiet is a 24dB fan, AF120 Quiet is 21dB, and the AF120 Performance is 30dB. Remember these are taken at 1m and the way they combine is non-linear. Two equal fans adds 3dB, four adds 6dB, and eight...