Tips on creating a VR benchmarking tool

We have some pretty steep requirements to run our VR software and want to release a benchmarking suite to give potential users a way to know if their machine will be adequate. Are there any tips to simulating VR load?

We want to test both CPU and GPU and include performance gains from things like instanced stereo. It would be great to be able to test instanced stereo without needing a headset attached to the machine during testing, much like VRMark does.