I got good service from Bike24 on a recent order of hubs, spokes, and tires. Prices are very good, and they let you order individual spokes for about the same price as other places that only sell by the box, so you can get the exact sizes you need and not have to buy extras if your wheels are less than 72 spokes. Shipping to the US is around $20 and it took a week, but the shipping cost was more than offset by the savings on other parts.