Learning the snatch

[Teo Silva]

Hi everyone,
I apologize for my ugly english but I'm italian:) ...

I'm a novice of the WL and I'm trying to learn the olympic lifts. Currently I'm learning the snatch and I'm following this progression:

1)Snath balance
2)Hang snatch from below the knees
3)Hang snatch from under the knees
4)Snatch

But I found hard to do the overhead squat.
How can I gain the necessary flexibilty to do that?
Do you think it's a good progression to learn the snatch?

Greetings.