Andi,
Yes I am sure I have the right CPU as I can run 64-bit guests in a nested ESXi 5.1 if vhv.enable = "TRUE" is globally set in /etc/vmware/config in the outer ESXi 5.1 or added to the vmx file by hand using my favorite text editor.
At the same time, the standalone Client has no "Expose hardware assisted virtualization to the guest OS" option. This fact is well-known among those who actively experiment with VHV. Hence my original question, how one is supposed to configure vmx-9 features in general if they don't want to pay for vCenter Server to get the Web Client.
Thanks!