No WHDload version exists because there is no need for a WHDload version. The game works well from hard drive with AGA and accelerators.
Depending on which set of (German) Disks you may have v1.01 which has some problems. The final German version was v1.05
http://aminet.net/package/game/patch/amber
and there are some patched versions of v1.05 to improve compatibility with the 68060
http://aminet.net/package/game/patch/amberfix
V1.07 (English) works well upto and including a 68060 "as is", it has known minor bugs though (mainly with typo's in the script files) as it is a beta release and was never sold commercially.