For 15 miles, if you wanted the Soho, I would put Trekking "butterfly" bars on it. This is a CHEAP upgrade. It gives you many hand positions to change it up (reduce fatigue). The bar fits hybrid bikes using their standard brake levers.
Nashbar Trekking Bars = $17
Ergon Grips = $28 (REI)
Cork Tape = $17 (LBS)