You don't need an autobooting hard drive. You can boot without autoboot! You boot from one drive and transfer everything to the other drive. It's pretty quick and works really well.
Here's what you do. Copy your Workbench floppy to DH0: Create a boot floppy, with ONLY an S directory, with Startup-Sequence in S/
In S/Startup-Sequence:
Assign SYS: DH0:
Assign C: SYS:C
Assign S: SYS:S
{Maybe need some more assigns here, I can't remember. Boot to the floppy without a Startup-Sequence and see what's assigned at boot time}
SYS:
Execute S:Startup-Sequence
That's it. You transfer booting from the floppy to the HD. This works in ANY version of AmigaOS, and I have done it many times for many reasons.