I'm in the
same boat - Amigas with 10base2 only. Pretty much anything
else I have that does networking has 10base2 _and_ an AUI at least.
My A3000 came with a network card with rj45, very lucky there.
I am wondering how hard it owuld be to remove the 10base2 transceiver
chip from the Amiga's network card and kludge on a 10baseT transciever
circuit. If the former is something standard like an 8392, it should be
pretty easy.
-tony