Thanks for the info, everyone. Might just do the Mavics if I can't find carbon clinchers.
In a perfect world I would just build my own carbon clincher 35-40mm rims, Sapim bladed spokes, white/CK fix/fix hubs. Sadly a) expensive and b) I don't have the requisite skill to build a wheel.
P.s. hamfoh, this is very strange but you and I will have almost the same setup for fg bikes. My Bolt will be the speed machine and I'm turning my 722 into a sweet townie (similar to yours). CREEEEEPY.