Board Connector / Footprint: DIN 41612 4slot x 96pin or 2x32pin 64 / 96 Pin connector, you can also fit 64pin edge connector in. These are high quality FR4 boards and also most likely cheapest you can buy.
8 slot Backplane Microbus Eurocard bus PCB 96pin 3U 32HP DIN 41612 FR4
ASUS Z97-K ATX LGA 1150 DDR3 4-Slot Motherboard CrossFireX USB 3.0
MSI MPG X570 Gaming Edge WiFi AMD X570 AM4 ATX DDR4 4-Slot PCIe SATA III
MSI Z390-A PRO ATX Intel LGA1151 DDR4 4-Slot Gaming Motherboard
MSI PRO B760-P DDR4 II ATX Intel LGA1700 Motherboard DDR4 4-Slot HDMI
MSI Z490-A PRO ATX LGA1200 DDR4 Intel Gaming Motherboard 4 Slot M.2
