19x ASUS mining expert board is fine to have the more number of cards in one rig. When comparing with the 1060 alone you may find the better performance from Rx 570 cards but still it one of the profitable card bro. Nvidia 1060 6GB also can use to mine the ethereum or ZEC.
Others like SSD, number of cards, OS, SMPS and the watts in SMPS according to the number of cards you gonna add in your rig should be decide by your own bro.