Have you tried pressing F5 during install at the point where it says press F6 to specify additional drivers?
In windows 2000 it then gives you a menu to select the type of computer you should try picking Standard PC instead of ACPI PC.
A friend of mine has whistler and the installer seemed very simmilar so i suspect it should have that option still.
I had a Gigabyte GA-5AA (got an Abit KT7-Raid and a Duron 600), I Wasnt too impressed with the Gigabyte BIOS`s myself, I thought 5AA.F3 was the latest Bios version.
From my use of the GA-5AA Bios version 1.3 seems to be the best id recomend you try that. you do not get ACPI mode using that either.