Questions about AsRock Z390 Phantom Gaming-ITX/ac

All graphics cards with PCIe fit on it (PCIe 3.0 16x). If you are using an ITX case, space is rather limited there. Height is usually enough. The length could be tight. (You can find this information in the specifications section of the enclosure).

Wireless LAN - Intel® 802.11ac WiFi Module - Supports IEEE 802.11a/b/g/n/ac - Supports Dual-Band (2.4/5 GHz) - Supports high speed wireless connections up to 1733Mbps - 2 antennas to support 2 (Transmit) x 2 (Receive) diversity technology - Supports Bluetooth 5.0 + High speed class II - Supports MU-MIMO Quelle: https://www.asrock.com/MB/Intel/Z390%20Phantom%20Gaming-ITXac/index.asp#Specification