Eleven81's AHD Stem securely holds your bars with a wide 4-bolt clamp. Stiff forged-aluminum construction means reasonable weight.
Stem angle is one of the factors that determines handlebar height. A listed angle of 0 degrees actually provides a rise of 16-20 degrees, depending on the bike's head-tube angle. Flexible, athletic riders prefer lower-rise stems, while recreational riders usually favor higher-rise stems.