Easiest option right now is probably an XSurf100 with a RapidRoad module - I think those are both still in good supply at a number of dealers. If you have another card that gives you a clockport you could get just the RapidRoad, although it won't be as fast. Bear in mind that there are two versions of the RapidRoad - one for clockports only and one for the XSurf100 or clockports.
Other options are Highway, Algor, Deneb, or Thylacine cards, but they're only available second-hand.
