The best way to transfer files from PC to Amiga (without an Ethernet connection) is to store them on 720K floppies. AmigaOS can read them if you activate the PC0 dosdriver.
I successfully used AmiTCP V3 on an A500 with Kick 2.0 and a total of 2.3MB RAM. There was enough memory left to run Yam and AMosaic. AmiTCP V3 comes on the Gold Fish Volume 2 CD. The full version of AmiTCP V2 is on Aminet. But I don't know if these work with Ethernet cards. I used a serial modem back then.
Bye,
Thomas