Why not a Cirrus Logic CS8900A ("Crystal
LAN")? These are very easy to
interface also (see C64 RRNet).
Well, I'm talking about what I know. The RTL is **very easy** to find
and there is plenty of source-code for PC for driving it. I don't know about
the Crystal LAN chip.
I like these as well, though they can require some
external programming.
Personally if I were going to offload TCP to another device I'd use one of
the Lantronix UDS series, which are nice all-in-one units.
But the Wizchip is so cheap! And so easy to use! Why use lantronix
(waaayyy expensive)???