Years ago I read something on Zipp's website stating that aero rims really don't matter much at depths below 38 mm (data from wind tunnel testing). I went with 28 spoke count hubs - already had 'em - Stan's Alpha 340 rims, and Sapim CX ray spokes. I used a Park tension meter, well worth it if you want to build your own wheels. I am very happy with the results, I truly can feel the difference accelerating and at speed. I weigh 160lbs. or so, I would go with an even lower spoke count if I was getting new hubs.