Thank you, Kevin.
Last night I did as you recommended--I removed the motherboard from the chassis and removed all wires, RAM, BIOS jumper, and CMOS battery. After ~1h, I plugged in the RAM, BIOS jumper, CMOS battery, main board power, fans, and F7 flashed 0160 (No HDDs, PCI add-ons, audio, FP USB, etc). At this point, I powered off, plugged in my C drive, and powered on. The system still will not boot. I ensured that SATA is configured to IDE and not AHCI.
When I get home today I will re-do this operation without RAM (I don't know if that had any effect on the operation).
Do you have any other suggestions? Assuming my original BIOS was one of the ones you listed, it looks as if reverting is not possible due to the reason I stated previously. I am stumped.
Thanks for your help,
Justin