I have a Powertap Pro Zipp rear wheel up for sale that might be what you're after. It is the earlier 404 style clincher rim, non-dimpled, aluminum braking surface, 32 straight gauge spokes -- basically similar to what Zipp is selling now as a "Clydesdale" version of the 404. It is durable enough to race and train on.
You can buy a new computer head and harness for about $300, and get the warranty, which I'd advise is a good thing. Their customer service is good, but they don't repair the CPUs (I had one fail and just bought a new one).
$500 plus shipping, email me at fredericksk --at-- comcast -- dot-- net for pictures.