RE: Dealers and Companies..
I have 13 left-handed bows in the shop right now in many major brands. For instance I have BowTech Tribute and Allegiance and Hoyt Trykon and Trykon XL, just to name a few.
From stocking them for many years, it has become well known that they are readily available in my shop. Working with the manufacturers so that cam switches can be made at a very nominal cost makes things easier.
Once you get established as a left-hand stocking shop, word will get around.