Get yourself over to Amibay. Plenty of new and exciting tech now available for ZIII machines to buy.
There are now all in one alternatives such as the ZORLAN-IDE-Clockport card with 10/100MB Network, IDE port using LIDE and a A1200 Fast Clockport for USB connectivity such as the Trident USB.
If you want something simpler, then an Individual Computers solution such as the X-Surf-100 with Z2 or Z3 modes at 10/100Mb LAN with a port for the RapidRoad USB module.
As for the Zulu SCSI. Good SD SCSI HDD replacement. The USB on those is for Firmware Updates and PC/MAC connectivity.