Actually I have a similar setup for getting data onto my external SCSI drive.

I connect the drive to my WinXP box (PCI SCSI card with 25pin external connector on the back) and use TransMac software to access the drive. Works grand so far, but I haven't tried formatting the external yet (it does give the option of formatting HFS and HFS+).

Works with any external drive (ZIP etc) but usual SCSI stuff applies (no hot swap obviously etc...).