with all due respect, I can't see why you want to add an IDE controller while you have the superior GVP scsi controller on the A530.
Amigan Rule #1 - If you have a SCSI controller on your accelerator, USE it ! It will give much better performance than any other solution
Amigan rule #2 - Always choose SCSI over IDE, exception may be the FAST ATA board on an A1200, but that can also be discussed.
As for ethernet, are you sure you have drivers for the USB-ethernet converter ?