First of all, it's normal for breakage to occur on the non drive side. (when it happens). IME the most likely spoke to break is the inside (head to outside) left side, followed by the outside left side.

There are lots of theories as to why this is true, and disagreement among experts, but the fact remains that it's true. Like the others, I'd replace the spokes on the left, but counter-intuitively, I'd use the lightest spoke with a 14g elbow. Also have the shop open up the elbow a bit when they thread the spokes, so it's cold set angle is closer to what angle the spoke actually sits at. The other thing to consider, is if there's enough room for a thin washer under the head to bring the elbow as close to the flange as possible.