The Winspace Hyper X 50mm are highly regarded, they have very good aerodynamic properties and are comfortably the fastest wheels you can buy in 50mm rim depth.
The Winspace hubs use standard 6000 series bearings of common sizes. This video shows you how to remove the bearings and replace them if they are worn or you want a bit more speed/durability.
It covers the service of the front hub, rear hub, rear freewheel. The part numbers are shown below.
Additionally, towards the end of the video there is a section covering grease, the merits of thick versus thin and what type to buy.
Things you will need:
Link to Winspace Website