Pagodeiro and Johnny have already given you some gret advice.
I´m a newbie too, but i´ll try to give my 2 cents:
I´ve had great success using A314 in sales. It really helps me to keep focused and unafected by setbacks. When i get a few bad answers in a row, i don´t even care. I have to visit clients, so i have to be at ease anywhere i go, and A314 helps me to feel good and confident everywhere, so it´s a good help.
However, if people goes to your shop instead o you going to their palces, maybe IG would be more suitable, as A314 sometimes makes me too focused and target oriented, ans some customers may feel a little intimidated.
I really like IS too. I had my first clear hits from an IS+IG combo, two sprays each.
There are some threads you may find useful. I guess their titles are self explainatory: