I don't want to discourage your Zipp purchase. Zipps are Zipps.
Nonetheless, I think you should consider something like this:
http://www.novemberbicycles.com/rfsc-wheelset/
http://www.boydcycling.com/38mm-carbon-clinchers/
psimet would likely be the more expensive option, but you could use Alchemy hubs from Broomfield. Local and lighter.