How to fight Organic tech?

[Davout]

I have just lost about 120 ships in combat(two separate attacks) to an Organic player. His damage was NEGLIGIBLE!!!!!
We are in late game, both have researched a lot of stuff. My ships were mostly Battle Cruisers and smaller ships with about 30 bigger ships. His were mostly Battle Cruisers and bigger.

What is a good combination of weapons(normal tech) to fight Organics ship for ship? His Lightning Rays and Enveloping Acid Globules do a lot of damage. And his Organic Armor is hard to get through and regenerates!

And what's with his weapons that are Large and Heavy mounts? What is that? When I browse his ship design he has a Heavy mount Phased-Polaron Beam that can do damage 180-165-165-165-150-150! What up with that! How come I(with normal tech) do not have Large and Heavy mounts? Or I do have them, but my ship designs do not distinguish between them?

Thanks