Hi Rich --
Have you given any thought to substituting 5.25" HD drives for the 8"s? Those old 8"s are difficult to keep running at this point in time. I had really good success with doing this with the Cromemco floppy controllers. It takes some doing to copy your old 8" media over, but you will have a much more robust system when you're done. If your controller card will support both 5.25" and 8" drives at the same time, the task of copying things will be much easier.
Roger