2. Seagate SATA drives can be configured to work at the lower speed.
3. SATA drives (at least Seagate's) have a jumper for this configuration, which is slightly smaller than the IDE jumpers I had sitting around.
4. The old jumpers can be made to work anyway.
5. Ubuntu's desktop install CD does not provide support for creating a RAID array during installation.
6. Ubuntu's live session does not include NFS mounting support.
7. But, the live session does include IP masquerading, so I can download the correct ISO image from another computer without swapping hard drives again, and try again in an hour.