Once you've selected a rim model, carefully compare several pairs and choose the smoothest before making the purchase. Fortunately, there's more consensus on spoke design than on rims. The best advice I can give is to use the strongest spokes you can get. Spoke strength has a great bearing on a wheel's reliability. DT, Wheelsmith, and Alpina.
Stainless steel is the best material for spokes.
Plated brass nipples are almost universally favored because of their low-friction threads, which make truing easier. Aluminum nipples, which save approximately one ounce per wheel, should be used only on special-purpose wheels destined for light duty. The price for saving that precious weight may be paid later in truing difficulties. Two gauges, or sizes, of spokes prevail. Remember that gauge numbers run opposite diameter size.