I have to fully agree with JPK. I am right handed but left eye dominate, so I do everything right handed except shoot a long gun. I learned to shoot on my Grandfather's Westly Richards SXS 12G despite the very annoying cast in the stock that favoured a right handed shooter. I will never reverse the controls on any firearm then when the s--- hits the fan and instincts take over, I am good with any standard gun. In fact with the M14, Sterling SMG and MAG58 I believe I have an advantage, but that is another story.

Based on my experience, I would recommend that a lefty does not reverse the controls but, at the very least, do look for a straight stock on a double rifle as the "fit" is vital.