Hi
I am pretty happy that i can report success! Ok, i still don't have any Linuxbios running... but yesterday i received the flashchips for the GA-M57SLI board. Already programmed with the F8 version of the original bios. The onboard bios was flashed to the F7 version. I have soldered a PLCC32 socket to the board and connected a switch to the open pads. I can now switch between the F7 and F8 version. I will post the details as time permits. The solution is quite neat and i think it is easier than desoldering a PLCC32 chip. Soldering is of curse still required but no desoldering.
Next stop will be actually flashing linuxbios.
Thanks for all who helped me out! ST