So I've settled on XFS for the RAID array. It's got some sweet features, and deals well with parallel or highly threaded workloads! But it has some strange quirks (disadvantages?).
For maximum performance the journal has to be stored separately from the RAID array, preferably on a device that can handle huge IOPS.
Secondly the disk check utility requires ginormous amounts of ram to run, and takes forever!
So my little, limping, SSD is going to become primarily a swap space, and journal space device. I hope I have enough room to cram the OS on their too...