[LigonierA1]

http://www.harborcountrybike.com/CAMPAGNOLO_KIT_NUCLEON_199902_REAR_COMPLETE_WHEEL_p/spok1041.htm

That's one option, Google "nucleon spoke kit" and you'll find many more. I have no idea if any of the results will actually have them in stock.

 

[LigonierA1]

Yeah, as I dust off the crevices of my mind I seem to recall that they are straight pull Sapin CXray spokes:

http://www.wheelbuilder.com/store/sapim-cxray-spoke.html