Campag Zonda on 8 speed Shimano

Well, my bike fund that I've been saving for a spring upgrade has unfortunately been spent on replacing the car. I've got a 2014 Giant Defy 5, I know it's not great but I guess another year on it won't hurt, and I'll appreciate the new bike even more when I get it. Besides the best gains can be made in my fitness, not saving weight.

I'm looking at upgrading the wheels as a few people have suggested it as an affordable upgrade that won't be wasted when I do change bikes. Campag Zonda's seem to be well reviewed, but are they compatible with 8 speed Shimano? Most of what I see is for 9/10/11 speed.

I'm planning on getting another 8 speed cassette to put on the Zonda's and using them in summer, and keep my old ones for winter use. Anything else I need to know about doing things this way?

Thanks