OK, I was able to run SystemRescueCd's USB creator by running it in Ubuntu Lucid. The USB stick booted, but when I ran GParted, it wasn't able to detect the RAID array.
Linux = FAIL.
The point of this exercise was to run GParted in order to resize our FreeBSD's /usr partition to make way for ZFS. I allocated around ~400GB of space to that partition, but I realized that it's better to use that space for ZFS since I'll be using it for jails.
FreeBSD jails + ZFS = WIN.
I'll just copy /usr to /var, resize it, and move back /usr to the new partition. I hope this works.
(this is probably GParted's fault, but I love to troll hahaha)