Update: I did end up using ReiserFS to copy all of my data to another NAS. It took days and days! Through that process I was able to identify the parity drive.
Eventually I decided to try the drives in another PC. I connected them to my daughters basic computer, booted with the same flash drive, configured the drives using the web interface, and voila, it was all back to normal
The only anomaly is that after a few minutes, it just "goes away". I can no longer access it using the web interface or browsing in My Computer. Not sure if this is related, but the monitor shuts down as well. After changing the PSU and having nothing change, I decided to let it work on the parity check overnight. Sure enough, in the morning, it was fine. Monitor is still blank but I run it dead head anyway.
So, the bottom line is, I was able to recover the data, and I was able to restore the tower. All hail unRAID.
And now I'm eyeing the Lian-Li PC-Q25B Builds thread
Thanks all for helping me in my hour of need and apologies for the belated reply, although in my defense, I didn't really get the thing back online until last night.