On the bright side, I feel like the single drive set up I have is 100% solid.
1GB Sys: ~35GB Work:, both SFS and attached to the Warp Engine SCSI. Gets over 9MB/s on diskspeed read and it's a 15K rpm drive, so access times are low for a spinning disk. Something like 5.6ms according to Seagate.
I've copied tens of GB to it since yesterday and no lockups, errors or partition wraparound. (I wrote a little script to just keep hammering it, copying data into a new folder each time)
Although I'd like to get a few more drives in it for redundancy, I'm not going to sweat it too much at this point. I'll be backing up to a CVS or SVN server periodically once I'm all set up.