HELP - want a carbon race wheel for a wired Powertap

I have an older wired Powertap laced to a nice 32 spoke DT swiss wheel. I am in the market for a carbon race wheel and wanted some recommendation since its hard to find a 32 hole carbon race wheel.

On a side note, what are ST or other wheelbuilder recommendations about the idea of lacing up a 24 hole wheel to a 32 hole PT hub(16 drive side, 8 non drive)? Any problems with safety, performance or watt readings?

Why does it have to be carbon? Why not get a nice light Alu rim?