If I'd been born 10-15 years earlier, I'd probably have been interested in this. I did grow up with the Amiga, but I was a child back then so I was mainly interested in gaming and programming with it.
These days I still maintain a small fleet of Amiga machines for hobbyist purposes but if I was going to do any instrument control I'd almost certainly do it with a standard PC. I do like the idea of data acquisition with the Amiga, though.
I think it would be very difficult to locate one of these expansion cards now.
BJH.