Spiraling in on the solution here. For perceivable aerodynamic improvement, I'd recommend the Velocity Cliffhanger, 32 bladed spokes (I build with Sapim CX-Sprint for most of my tandem wheels), and a tire that's labelled 25-28mm. The tire will balloon up to 30-32mm inflated on those rims. Hubs: either White Industries XMR or DT Swiss 350.
For a lifetime of durability, same as above with 36 spokes.
For *looking* aero, go with the Aforce AL33 with 32 spokes. They're optimized for 23mm tires. With 30mm tires, they're just as aero as box rims.
For a lighter weight solution that looks aero (but really isn't), go with the Kinlin XR31T rims. They'll spin up faster than the other options here, but your cruising speed and top speed will be lower than with the Cliffhangers.