I have an old 10Base-t / 14.4 modem PCMCIA card, its made by Megerhertz (called the em1144t or something), it works okay with Linux, haven't tried with Aos, you think it would work?
I don't have my amiga with me, but next time I go to my parents house I'm gonna have a play, see If it will work with my miggy. :-D