Hi. I'm a left handed fighter also. I've been training muay thai for 16 years. When I first started training, I usually fought in a right lead stance because it was more natural for me as a lefty, but once I started sparring more, I discovered that I could counter more effectively when standing the same as my opponent. So I began training in both stances, but now I prefer to fight in a left lead stance. One advantage you will have is being able to quickly develop a devastating jab w/ your left hand as your lead. Greg