What is the best dual mining option with Zcash?

Hi,

What is the best dual mining option for Zcash with 1070 cards??

Where you don't take a noticeable hit in H/S, none.

Nein. Nada.

That being said, you can use a CPU miner concurrently with Zcash miner. You can mine BCN, XMR with CPU if you have decent CPU and don't mind extra heat.