Very good info, Im over in Edmonton and have never tried to go the SSD way on the actual Flyer drives.
TL;dr SSD is not the same thing as CF card.
Just to be clear, unless it is an SSD that has load balancing built into the controller to support classic machines that don't have it built into the operating system, you should NOT use it. The Flyer really thrashes a drive with constant writing, deleting, and moving data that a typical SSD designed with Windows, Mac, or Linux in mind will die quickly. Those operating systems have load balancing built in so they manage it themselves. Just attaching one of these drives with an interface adapter like IDE to SCSI 2 won't address the issue.
Operating systems like Amiga OS, or more accurately the Flyer's OS, does not know anything about load balancing so parts of the "drive" will be repeatedly rewritten. Eventually elements will no longer hold data. That is why SSDs have a little extra memory to pad out for that loss. Load balancing does just what the name says - it spreads operations across the whole device so no one part wears out significantly sooner than the rest.
Drives like some OWB models are designed for classic operating systems that don't know anything about load balancing. The drive has load balancing routines built into its controller. As far as the operating system is concerned, it looks like a regular hard drive that sequentially writes sectors to it while the drive is actually scattering them around to balance the wear.
Besides drives like the OWB ones, Compact Flash cards have this built in. They were originally designed for digital cameras which do a lot of rewriting so the engineers did a smart thing that really paid off later as they were used as primary drives by including the load balancing in them.
This may have been a totally unnecessary discussion but wanted to make sure that we were talking about the same thing. You said SSD in your reply. You may have just used it as a general term that I includes all solid state drives. Unfortunately, in a couple of features like this, CF cards are quite different from an SSD that is typically used as a primary drive.
Those SSD drives like the OWBs are frightfully expensive - hundreds of dollars for just 120 GB. Several times more expensive than the "regular" SSDs. A similarly sized CF card is less than 20 dollars. It's better to put some of that money into a quality adapter. You can use the SD to SCSI adapters but as I originally mentioned they have a transfer speed that is half of what is required for HQ5. To use as a Flyer video drive, you really do need to use a CF card with a quality adapter like the Acard that supports at least 5 MB/s or blow a wad of cash for 2 or 3 OWB drives. Any less and it will drop frames. The audio drive doesn't require the transfer speed that the video drives do so you can fudge it a bit with it.
Also remember that whatever adapter you use, it has to have SCSI 2 on the side that plugs into the Flyer and has to have SCSI termination built into it or you will have to use a termination pack.
Sorry if this is basic stuff that you already know. As I said, just wanted to make sure that our assumptions were the same