Setup the 1gb RPI4 as a NAS with a 1TB HDD. Transfer speeds of big files are 100-120MBps both read and write over gigabit network. Really happy with the speeds. If its reliable will get a 4tb drive or 2 of them and attach it. Extended the network with a daisychained switch. Router->gigabit switch->gigabit switch.
Will be checking how good it is over the month. Will add more stuff via Docker.
Also got an SSD and powered USB to extend it. Figuring out a more elaborate setup.