Not sure what size you are trying to build or it's intent but I just posted a custom set Down Cycles (AJ) built for me 1 year ago. It's stans flow rims 26" with dt swiss double butted spokes and red hope pro II evo hubs. These are convertible to any axle size; both front and rear.
maybe it's not custom custom, but carbon 29er, I'd like someone to convince me that I need the Enve xc 29er wheels. I've been thinking about getting a new bike, but can't find anything I like better than what I have so that leaves me with upgrades.