I would highly recommend to update the design to 32-bit fast memory. This 16-bit memory can't be called fast: The ACA620 clocked at 16.67MHz beats the FuriaEC020 by almost 600 Dhrystones. If you overclock the ACA620, it beats this card by over 1400 Dhrystones.
The EC020 processor can do *much* more than this. It's worth continuing the development here - you're on the right path!