Well maybe an other approach that is a little difficult to set up (I don't know how to do it excactly too)
Try to get an A560 Arcnetadapter für the A500, and an A2060 Arcnetcard for a Zorroamiga. Put in that Zorroamiga an Ethernetboard too. Using MiamiDX it should be possible to rout the broadbandconnection of the Zorroamiga to the A500 via the arcnetconnection.
