Try to thinking this way: just buy used on eBay IBM-branded RAID card (or LSI, Dell, Adaptec, MSI, SiliconImage), better PCI-X 2 or 2.1, install two HDD (I suggest bullet-proof Ultrastar 7K3000 3TB 3.5-INCH ENTERPRISE HARD DRIVE SATA model HUA723030ALA640), configure to mirror and sleep well another 5 years. :)
You cannot write exactly where failure happened (in appliance or desktop), so I decide that You have desktop system.
Better to spend $50 on card and sleep well 5 years rather spending hours with failed drive and dancing around ZFS.