Any update on the page you suggested yesterday? Or maybe a sapphire 280 dual-x recommended bios? Thanks

No, not yet. But in the interim, here are some of my modified BIOS files and their respective models/voltages. I've also included a copy of ATIWinFlash. Furthermore, I have an ASUS bios and a Gigabyte BIOS, just not on me at the moment. Will upload later.
https://www.dropbox.com/sh/g894zll2mrsd7gy/hEnCekUOmZNOTE: I highly recommend you back up your stock BIOS. I only have the Toxic stock in their now but will upload the rest soon as I get home.
The numbers correspond to the voltage and I have only included one's that have been running stable for me with the following config:
--scrypt-jane --sj-nfmin 4 --sj-nfmax 30 --sj-time 1388361600 -I 12 --gpu-engine 1000 --gpu-memclock 1250 -w 256 -g 2 --auto-fan --temp-target 75 --temp-overheat 80 --temp-cutoff 85 --thread-concurrency 16384
A good, full Windows guide can be found here if you want to experiment with additional voltages:
http://releasethecrypto.com/undervolting.html