Building up an urban fixie or townie bike? Then you just have to have the classic Bull Horn Bars from Sunlite. They're made from aluminum with a steel center sleeve, so they're light, stiff and durable.
Which Reach and Drop you prefer depends on your hand size, arm length and riding style. If you like what you're riding, simply match it as closely as possible. In general, deeper drops and longer reaches are appropriate for riders with long arms and large hands while narrow drops and short reaches fit smaller riders. Handlebar Width is related to shoulder width. Riders usually prefer a handlebar width equal to the measurement between their shoulder blades, or slightly wider if they climb a lot or ride fast and hard.