Nvidia with ESXi hosts that can't take a GPU card.

So I was wondering would something like the Nvidia VCA work to enable vGPU for VDI with Horizon View 7.x.
http://www.nvidia.com/object/visual-computing-appliance.html

And if so would it integrate with the VM’s or the hosts directly?

I ask because our VDI cluster can’t accept a addin graphics card (IE the hosts don’t have any room for expansion.