Why brass? (Just curious).

I think 14/15g double butted spokes are probably a good durability for the weight.

You can probably build a good, durable wheelset for $500 or less. I don't have much experience with Velocity, Mavic, or DT Swiss rims, but I can say that Shimano hubs are quite durable (and are QUIET). Criss King hubs have that classic CK freewheel sound that some people love.