i don’t know power consumption of apu-board, r64 is ~6W without additional wifi-card
you can use fron pci-slot for wifi-card (to get second AP, using internal wifi for first) and using sata (disables second pcie-slot) to attach ssd/hdd. you can use sd-card imho up to 128GB (only tested 32/64GB) and using 8GB emmc. RAM-upgrade not possible…1G is soldered