Help for a "Lefty" to buy the right circular saw
In my opinion, it really dosen't matter. For certain cuts I need my left hand, others my right. Go to your local store and try handling all the saws. Pick the one that feels best to you. Hint. The worm drive saws adapt well to both right and left hands.
With power tools, where you want accuracy, it is frustrating at times. To counter that, I use a straight-edge as a guide to help me whenever possible ... a speed square or a long, metal straight edge that I can clamp to my work.
A left handed saw is certainly most beneficial for a left handed person. The balance, control and safety is designed for a left handed person. Awkward and unsafe any other way. When making a cut hold saw in left hand. Sight with left eye. Scrap falls to left. Good wood is held with right hand. All other variations of use is a safety issue. For sure.
Porter Cable # 743 is a great tool.
Porter Cab,e # 345 is also pretty cool with a 6" blade that cuts dimensional materials.
I'm sure there are newer tools that work great.