Of the choice between the X-Surf and Ariadne, I'd go with the Ariadne. You might be interested to look around and find some benchmarks of various Amiga ethernet solutions. I know we posted an X-Surf vs. old C= ethernet board comparison on here before...
The Mediator or Prometheus are probably the fastest and most modern solutions now, though. (Of course, depending on how you want to set this stuff up, you may need a new case...)
