Dara.  In Khmer (Cambodian language), it's a great boy's name, but in English it seems people think of it as feminine. 

Thanks for the well-reasoned replies!  We've had the same concerns about pronunciation and perceived gender.  We're in a Northeastern city, so plenty of diversity in names along with large Irish and Cambodian populations.  We'll keep looking for now, but Dara's definitely in the running for a first or middle name.