i read one of the post regarding mounting the supesat 3 horizontal not vertical... As a technician idont see why position will affect the physics of it.. I have 4 supersat 3 for surround 7.1. And i just bought them 3 days ago.. And mounted horizontally

The "C" versions are designed for horizontal mounting. The tweeter's dispersion pattern is not identical - horizontal does not equal vertical dispersion so the tweeter is rotated in the "C" versions so the speaker has good horizontal dispersion when sideways.

Ask your dealer to exchange them for you - they should have sold you "C" if they knew of your mounting intentions.

Would you recommend them mounted vertically or horizontally? With the right speaker?...envelopement wise?

As long as the correct speaker is used they are virtually identical vertically or horizontally, so whatever fits best in your setup is the way to go.