F18k here - https://forums.tweaktown.com/gigaby...-bios.html?s=086519123979b4623ccae8d246afdc94
I wouldnt worry about it saying beta, all the ones with letters are, the final versions are just F then a number, so if there was an F18 then that would be the official one for the F18* series, so all the ones a,b,c,d, etc go into the final BIOS.
So I've done some more investigation and it's a rev 1.1 board. The latest bios available direct from Gigabyte is F18i. I'm gonna try and get hold of an adapter from the hardware store tomorrow - if it's open.