Im not a fan of the 123 program - just my personal values, it didnt sit right with me.
Other things Ive been suggested are Circle of Security and Positive Parenting.

It all depends on your values and what kind of parenting style you believe suits you.

From what I have heard though - 2 child therapists and my own counsellor have said that if I can get into circle of security to jump on it because it is very very good