You don't have to pay for modded BIIOS. Yu can find one on Youtube. Search for "buriedone elpida" video. Its very good. I'm using it myself. I can get my Nitro up to 31MH/s. You canalso mod the BIOS by yourself. Anorak forum has the tutorial using Hexedit.
Ok so the only issue with this is the rom they provided is only 256, I know atiflash wants 512.
It's not necessary.