vGPU and vSGA simultaneously

I have 2 K1 cards in 1 Dell R720 host. Will it be possible to designate 1 GPU or 1 card as vGPU but leave the remaining GPUs available for vSGA?

No.

As per the deployment guide for vGPU on vSphere, vGPU and vSGA are mutually exclusive and cannot be deployed on the same host.