Well, it depends on the PURPOSE you want to teach them sign language.
Is it as an ESL tool, or for Communication??? Will they travel???
I know I taught American sign here in HK, even though it �s a former British colony. However, I was just using it as an ESL tool, but I found I had to communicate in sign to aomeone when I saught information from the Deaf Sociaty of HK ... soo interesting and I was so slow ha!
Anyway, I found this site which teaches the letters. This was great for my pre-schoolers!!!!
Its �Starfall � ... just click on the �HANDS � down the bottom
So ... it �s up to you. EITHER standard would be fine and they will learn a useful skill.