The only way to fit it in an A4000 would be to take the A500 version and build some sort of converter to fit it in a Zorro-slot. I've seen people who did this the other way around (to connect Zorro-II cards to the A500 side expansion slot), so it should be possible. AFAIK there never was an converting device to fit the cartridge in an actual Z-II slot.
So, the only option would be some DIY thing I guess...
