Yeah, SD media is pretty cheap. Like Unknown_K says, you can find slightly modern drives too. 68 pin drives may be a little easier to convert to 50 pin SCSI. Real HDs when they are working seem to be easier to setup, but most drives I run into are really loud so I prefer solid state solutions for a main machine. The SCA drives are fairly quiet though but can run a little hot. If you run something like System 7.6.1, maybe even 7.5.5, you can use the whole drive if it's large. I make 2 x 2GB partitions for booting/compatibility and then format the rest of the drive as a third partition.