There's a number of mining-specific motherboards compatible with kaby lake processors.
Asus B250 Mining Expert
19 slots seems like overkill for your purposes, and note that actually getting 19 cards to run on this board is usually a pain. (That many cards on one system isn't always desirable either, since it puts many eggs in one basket, so to speak.)
ASRock H110 Pro BTC+
13 slots, spaced rather close together, however.
BIOSTAR TB250-BTC PRO
This one seems to have more quality control issues than others, or such reports could be due to simple user error and chance.
GIGABYTE GA-H110-D3A
Additionally, you may wish to consider motherboards that aren't marketed for mining purposes. Just make sure you do the necessary research to see if other people have run into limitations with that specific board.
Thanks alot.
I was reading somewhere and am probably wrong that we can't run more than 8 cards due to some limitation in some mining software?
In your experience do I need to flash some special BIOS on the above MBs or they just run out of the box?
Thanks
At this time, Windows 10 drivers will only allow you to run up to 8 Nvidia GPUs and 8 AMD GPUs. Most Linux distributions work fine with more than 8 GPUs from Nvidia xor AMD, but mixing between the two on one system is difficult to get running on many Linux distributions. The 19-slot ASUS board is supposed to be able to handle more than 13 cards if you have P106-based cards available.
Usually the mining-specific motherboards will work out of the box, but I haven't personally used all of the ones I listed (notably ASUS's 19-slot board). Occasionally, a BIOS update will be desirable, if you're troubleshooting a rig.