Before you buy your boots, make sure to see reviews on the boots:
Snowboard Boots Reviews - Buzzillions.com
The Men's Burton Moto Boot got the top reviews (4.3 out of 5 stars), and 100% of people said that the width and sizing feels true to size:
Pros:
Comfortable, Quality construction, Warm, Adjustability
Best Uses:
Downhill (5), Park (5), Half pipe (4)
Sizing/Fit:
100% agreed the width feels true to width
100% agreed the sizing feels true to size