The script layout you mentioned, with separate audio and video columns, is exactly right.
It's the only way to do it.
Just for the record, the initial script doesn't need to contain too much camera direction.
Once the director gets hold of it, he (she) will produce a shooting script from your original. The shooting script instructs the camera and also times every shot.
If you'd care to mail me, I'll send you an example of script layout.
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