This very question was asked and answered just a few weeks ago. Here's some info.
http://branfordbike.com/articles/cas...-cogs-pg60.htm
Any Campy 8 speed cassette will work, but most places that still sell them have few to choose from.
At one time, you could easily buy a 9/10/11 speed cassette body to fit this hub, but that was a long time ago. Finding one now will not be so easy.
Try a search. Someone listed some possible options. IMO, it's not worth the trouble and expense to change the hub over to 9/10/11 splines.