Some useful links and tidbits picked up during my research.

• If you want to run ZFS under FreeBSD, FreeNAS now supports it. I prefer a Solaris UI and I need something more generic than a file server.
• Stuff I need to run on this server: Squid web cache; HPLIP/CUPS print server; BIND; syslog & logwatch; rsyncs to DataTank; automatic snapshots.
• Thinking I might as well dump the USB boot stick and install the OS directly to the mirrored disk pool. It looks like those disks will need to be kept spinning anyway, my data storage needs are currently modest and I gain the protection of mirroring without worrying about Flash write limitations. (I’m guessing USB Flash would be crap as a ZIL device, right?)
• Best ZFS recordsize for Squid is the default 128K, with atime turned off.
• Still wondering what to do with all the redundant IDE drives I’m going to accumulate. I’ve only ever found one cheap multibay enclosure and that seems to be unavailable now. Even then, I don’t think I actually have a purpose for that storage, and they’re not cheap to run.
• OpenIndiana now supports virtual consoles (again).