I've looked in the archives, and apparently it is possible to use 9/10 speed wheels on an 8 speed setup: "You can get a Campy 8 speed spacer conversion kit and then a 'losse cog'-Veloce 9 speed cassette. You leave out the largest cog (ie) 26t and assemble on the cassette body using the conversion kit spacers and it works perfect."

However, I have the following questions-
-Where do I get the 8 speed conversion kit? (I can't find it on Branford's site)
-Why can't I just use my old 8 speed spacers?
-Should I run a 9 speed chain?
-If I run a 9 speed chain, I should change the jockey wheels, right?

thanks!

http://www.branfordbike.com/cassette/cog11.html#item1

The branford site says to use a Rohloff 8 speed chain for best results.

You current 8 speed spacers won't work because the 9 speed cogs are thinner, so thicker spacers are needed.

Hello
Why not try and source an 8 speed cassette? You can still get them and it should work on a 9/10 speed hub without any special spacers.
I run 8 speed Athena on my training bike with a 9 speed Veloce hub. The 8 speed cassette all fits fine. I even use that 9 speed wheel on my good bike which is 10 speed Record (smug mode!) for sunny training rides. As you probably know, the overall width of 8, 9 and 10 speed cassettes is near enough the same. This is done with thinner spacers and thinner sprockets on the 9 and 10 speed cassettes. Forgive me if you know all this.

Happy hunting. :)