HP Workstation and GPU for Deep Learning

I’m getting a new HP Workstation Z640. At HP and NVIDIA websites the only GPU appropriate for Deep Learning seems to be Tesla K40 which is not the best option (performance vs cost).

http://www.nvidia.com/object/hp_workstations.html

Is there a newer card I could use for Deep Learning on HP Workstation Z640?

Was thinking something like Titan or Geforce GTX 1080Ti.​

Thanks
Dimitris

If you buy a workstation from a big integrator without a GPU first, with the goal of adding a GPU yourself later, make sure that a sufficiently powerful power supply is included.

In my experience, such workstation vendors tend to pick from multiple different PSUs for a given computer model, and will install the smallest model capable of supporting the peripherals you specify when you buy the machine. Big vendors also have a tendency to use customized components and the PSUs and cable connectors used may not necessarily be standard ones, so it could be more difficult to upgrade the PSU later on.