There are other options also.
PlipBox connects to paraller port, you can found one here.
Lattests option is 7-Bit's SPI Masterbus Clockport, wich connects to clock port, IF you have one. Clock port can be found several Amiga Addon cards like Buddha IDE controller. There is a SPI driver for a enc28j60 NIC (price 2€). Wich you would need to buy separately. SPI Masterbus Clockport allows you to connect SPI bus devices to your Amiga. Driver needed currently there is a SD card and LAN drivers.