Bensheim,
If you have not already done so, you can review additional product information at the manufacturer's site:
Storage Depot.
The Storage Depot "Contact Us" option includes phone and fax numbers as well as an email address for technical support.
If I am understanding correctly, you want a replacement optical drive which will do two things for a Macintosh running Mac OS 9:
   A. boot from an operating system installer when necessary.
   B. burn CDs.
I have no intention of trying to boot from that drive as an experiment!!!
I have some sense of your hesitancy. Nevertheless, I am not sure why you have no intention of pushing the hardware to its limits to determine what your current situation is.
In addition, I am not sure what your options are for burning a CD in Mac OS 9 using another optical drive. As far as I know, PatchBurn and Toast are not options in Mac OS 9.