Just filed it Saturday for B2 extension.
I just filed I-134 for B2 extension. For "Dependents", I put whoever needs the B2 extension. This is the 3rd time I used I-134 and I don't see problem with that.
In addition to I-134, you can consider including:
1. taxt form
2. W-2
3. bank statements (2-3 months)
4. paycheck stub.