I am also lefthanded, but back in 1966 there were no lefthanded teachers, and fewer lefthanded basses, not to mention my single mom with 4 kids could not afford one. So the teacher I found told me if I learned to play righthanded my fast hand would be on the neck making me a better player. So thats how I learned, but the only drawback I have is I can not use a pick very well. I like the sound of fingers better anyway,so for me not much of a drawback there.
One more thing to think about is if you play righthanded, you can always sit in at a jam without hauling your ax and pick up any bass in a store to try it out.
best of luck to you
G&L Club Member #406 Wisconsin Bassist Club #73 Fretless Club Member#706