Recently built a X99 build in a DanCase A4-SFX. I'll include inside pics if there is interest.
Specs:
core i7 6850K
32GB 2800Mhz RAM
GTX 1080Ti FE
2x5TB HDDs
1x512GB NVMe SSD
1x500GB SATA SSD
Corsair SF600
Audeze LCD 4
I have used Dynatron T318 with a Noctua fan as the CPU Cooler. I am getting great temps imo, 52C-55C idle, 70-72C Gaming(Mass Effect Andromeda, Assassin's Creed Origins), 82-85C Prime95 10 mins. CPU is overclocked by 300Mhz and undervolted by 50mV.
GPU Temps are 50C idle and 85-87C gaming.